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30<li><a href="async_context.html" class="nav-async_context">Asynchronous context tracking</a></li>
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113          <ul>
114            <li class="pinned-header">Node.js v18.20.1</li>
115            
116    <li class="picker-header">
117      <a href="#">
118        <span class="collapsed-arrow">&#x25ba;</span><span class="expanded-arrow">&#x25bc;</span>
119        Table of contents
120      </a>
121
122      <div class="picker"><div class="toc"><ul>
123<li><span class="stability_2"><a href="#console">Console</a></span>
124<ul>
125<li><a href="#class-console">Class: <code>Console</code></a>
126<ul>
127<li><a href="#new-consolestdout-stderr-ignoreerrors"><code>new Console(stdout[, stderr][, ignoreErrors])</code></a></li>
128<li><a href="#new-consoleoptions"><code>new Console(options)</code></a></li>
129<li><a href="#consoleassertvalue-message"><code>console.assert(value[, ...message])</code></a></li>
130<li><a href="#consoleclear"><code>console.clear()</code></a></li>
131<li><a href="#consolecountlabel"><code>console.count([label])</code></a></li>
132<li><a href="#consolecountresetlabel"><code>console.countReset([label])</code></a></li>
133<li><a href="#consoledebugdata-args"><code>console.debug(data[, ...args])</code></a></li>
134<li><a href="#consoledirobj-options"><code>console.dir(obj[, options])</code></a></li>
135<li><a href="#consoledirxmldata"><code>console.dirxml(...data)</code></a></li>
136<li><a href="#consoleerrordata-args"><code>console.error([data][, ...args])</code></a></li>
137<li><a href="#consolegrouplabel"><code>console.group([...label])</code></a></li>
138<li><a href="#consolegroupcollapsed"><code>console.groupCollapsed()</code></a></li>
139<li><a href="#consolegroupend"><code>console.groupEnd()</code></a></li>
140<li><a href="#consoleinfodata-args"><code>console.info([data][, ...args])</code></a></li>
141<li><a href="#consolelogdata-args"><code>console.log([data][, ...args])</code></a></li>
142<li><a href="#consoletabletabulardata-properties"><code>console.table(tabularData[, properties])</code></a></li>
143<li><a href="#consoletimelabel"><code>console.time([label])</code></a></li>
144<li><a href="#consoletimeendlabel"><code>console.timeEnd([label])</code></a></li>
145<li><a href="#consoletimeloglabel-data"><code>console.timeLog([label][, ...data])</code></a></li>
146<li><a href="#consoletracemessage-args"><code>console.trace([message][, ...args])</code></a></li>
147<li><a href="#consolewarndata-args"><code>console.warn([data][, ...args])</code></a></li>
148</ul>
149</li>
150<li><a href="#inspector-only-methods">Inspector only methods</a>
151<ul>
152<li><a href="#consoleprofilelabel"><code>console.profile([label])</code></a></li>
153<li><a href="#consoleprofileendlabel"><code>console.profileEnd([label])</code></a></li>
154<li><a href="#consoletimestamplabel"><code>console.timeStamp([label])</code></a></li>
155</ul>
156</li>
157</ul>
158</li>
159</ul></div></div>
160    </li>
161  
162            
163    <li class="picker-header">
164      <a href="#">
165        <span class="collapsed-arrow">&#x25ba;</span><span class="expanded-arrow">&#x25bc;</span>
166        Index
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168
169      <div class="picker"><ul>
170<li><a href="documentation.html" class="nav-documentation">About this documentation</a></li>
171<li><a href="synopsis.html" class="nav-synopsis">Usage and example</a></li>
172
173      <li>
174        <a href="index.html">Index</a>
175      </li>
176    </ul>
177  
178<hr class="line">
179<ul>
180<li><a href="assert.html" class="nav-assert">Assertion testing</a></li>
181<li><a href="async_context.html" class="nav-async_context">Asynchronous context tracking</a></li>
182<li><a href="async_hooks.html" class="nav-async_hooks">Async hooks</a></li>
183<li><a href="buffer.html" class="nav-buffer">Buffer</a></li>
184<li><a href="addons.html" class="nav-addons">C++ addons</a></li>
185<li><a href="n-api.html" class="nav-n-api">C/C++ addons with Node-API</a></li>
186<li><a href="embedding.html" class="nav-embedding">C++ embedder API</a></li>
187<li><a href="child_process.html" class="nav-child_process">Child processes</a></li>
188<li><a href="cluster.html" class="nav-cluster">Cluster</a></li>
189<li><a href="cli.html" class="nav-cli">Command-line options</a></li>
190<li><a href="console.html" class="nav-console active">Console</a></li>
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203<li><a href="http2.html" class="nav-http2">HTTP/2</a></li>
204<li><a href="https.html" class="nav-https">HTTPS</a></li>
205<li><a href="inspector.html" class="nav-inspector">Inspector</a></li>
206<li><a href="intl.html" class="nav-intl">Internationalization</a></li>
207<li><a href="modules.html" class="nav-modules">Modules: CommonJS modules</a></li>
208<li><a href="esm.html" class="nav-esm">Modules: ECMAScript modules</a></li>
209<li><a href="module.html" class="nav-module">Modules: <code>node:module</code> API</a></li>
210<li><a href="packages.html" class="nav-packages">Modules: Packages</a></li>
211<li><a href="net.html" class="nav-net">Net</a></li>
212<li><a href="os.html" class="nav-os">OS</a></li>
213<li><a href="path.html" class="nav-path">Path</a></li>
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215<li><a href="permissions.html" class="nav-permissions">Permissions</a></li>
216<li><a href="process.html" class="nav-process">Process</a></li>
217<li><a href="punycode.html" class="nav-punycode">Punycode</a></li>
218<li><a href="querystring.html" class="nav-querystring">Query strings</a></li>
219<li><a href="readline.html" class="nav-readline">Readline</a></li>
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221<li><a href="report.html" class="nav-report">Report</a></li>
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223<li><a href="stream.html" class="nav-stream">Stream</a></li>
224<li><a href="string_decoder.html" class="nav-string_decoder">String decoder</a></li>
225<li><a href="test.html" class="nav-test">Test runner</a></li>
226<li><a href="timers.html" class="nav-timers">Timers</a></li>
227<li><a href="tls.html" class="nav-tls">TLS/SSL</a></li>
228<li><a href="tracing.html" class="nav-tracing">Trace events</a></li>
229<li><a href="tty.html" class="nav-tty">TTY</a></li>
230<li><a href="dgram.html" class="nav-dgram">UDP/datagram</a></li>
231<li><a href="url.html" class="nav-url">URL</a></li>
232<li><a href="util.html" class="nav-util">Utilities</a></li>
233<li><a href="v8.html" class="nav-v8">V8</a></li>
234<li><a href="vm.html" class="nav-vm">VM</a></li>
235<li><a href="wasi.html" class="nav-wasi">WASI</a></li>
236<li><a href="webcrypto.html" class="nav-webcrypto">Web Crypto API</a></li>
237<li><a href="webstreams.html" class="nav-webstreams">Web Streams API</a></li>
238<li><a href="worker_threads.html" class="nav-worker_threads">Worker threads</a></li>
239<li><a href="zlib.html" class="nav-zlib">Zlib</a></li>
240</ul>
241<hr class="line">
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243<li><a href="https://github.com/nodejs/node" class="nav-https-github-com-nodejs-node">Code repository and issue tracker</a></li>
244</ul></div>
245    </li>
246  
247            
248    <li class="picker-header">
249      <a href="#">
250        <span class="collapsed-arrow">&#x25ba;</span><span class="expanded-arrow">&#x25bc;</span>
251        Other versions
252      </a>
253      <div class="picker"><ol id="alt-docs"><li><a href="https://nodejs.org/docs/latest-v21.x/api/console.html">21.x</a></li>
254<li><a href="https://nodejs.org/docs/latest-v20.x/api/console.html">20.x <b>LTS</b></a></li>
255<li><a href="https://nodejs.org/docs/latest-v19.x/api/console.html">19.x</a></li>
256<li><a href="https://nodejs.org/docs/latest-v18.x/api/console.html">18.x <b>LTS</b></a></li>
257<li><a href="https://nodejs.org/docs/latest-v17.x/api/console.html">17.x</a></li>
258<li><a href="https://nodejs.org/docs/latest-v16.x/api/console.html">16.x</a></li>
259<li><a href="https://nodejs.org/docs/latest-v15.x/api/console.html">15.x</a></li>
260<li><a href="https://nodejs.org/docs/latest-v14.x/api/console.html">14.x</a></li>
261<li><a href="https://nodejs.org/docs/latest-v13.x/api/console.html">13.x</a></li>
262<li><a href="https://nodejs.org/docs/latest-v12.x/api/console.html">12.x</a></li>
263<li><a href="https://nodejs.org/docs/latest-v11.x/api/console.html">11.x</a></li>
264<li><a href="https://nodejs.org/docs/latest-v10.x/api/console.html">10.x</a></li>
265<li><a href="https://nodejs.org/docs/latest-v9.x/api/console.html">9.x</a></li>
266<li><a href="https://nodejs.org/docs/latest-v8.x/api/console.html">8.x</a></li>
267<li><a href="https://nodejs.org/docs/latest-v7.x/api/console.html">7.x</a></li>
268<li><a href="https://nodejs.org/docs/latest-v6.x/api/console.html">6.x</a></li>
269<li><a href="https://nodejs.org/docs/latest-v5.x/api/console.html">5.x</a></li>
270<li><a href="https://nodejs.org/docs/latest-v4.x/api/console.html">4.x</a></li>
271<li><a href="https://nodejs.org/docs/latest-v0.12.x/api/console.html">0.12.x</a></li>
272<li><a href="https://nodejs.org/docs/latest-v0.10.x/api/console.html">0.10.x</a></li></ol></div>
273    </li>
274  
275            <li class="picker-header">
276              <a href="#">
277                <span class="collapsed-arrow">&#x25ba;</span><span class="expanded-arrow">&#x25bc;</span>
278                Options
279              </a>
280        
281              <div class="picker">
282                <ul>
283                  <li>
284                    <a href="all.html">View on single page</a>
285                  </li>
286                  <li>
287                    <a href="console.json">View as JSON</a>
288                  </li>
289                  <li class="edit_on_github"><a href="https://github.com/nodejs/node/edit/main/doc/api/console.md">Edit on GitHub</a></li>    
290                </ul>
291              </div>
292            </li>
293          </ul>
294        </div>
295        <hr>
296      </header>
297
298      <details id="toc" open><summary>Table of contents</summary><ul>
299<li><span class="stability_2"><a href="#console">Console</a></span>
300<ul>
301<li><a href="#class-console">Class: <code>Console</code></a>
302<ul>
303<li><a href="#new-consolestdout-stderr-ignoreerrors"><code>new Console(stdout[, stderr][, ignoreErrors])</code></a></li>
304<li><a href="#new-consoleoptions"><code>new Console(options)</code></a></li>
305<li><a href="#consoleassertvalue-message"><code>console.assert(value[, ...message])</code></a></li>
306<li><a href="#consoleclear"><code>console.clear()</code></a></li>
307<li><a href="#consolecountlabel"><code>console.count([label])</code></a></li>
308<li><a href="#consolecountresetlabel"><code>console.countReset([label])</code></a></li>
309<li><a href="#consoledebugdata-args"><code>console.debug(data[, ...args])</code></a></li>
310<li><a href="#consoledirobj-options"><code>console.dir(obj[, options])</code></a></li>
311<li><a href="#consoledirxmldata"><code>console.dirxml(...data)</code></a></li>
312<li><a href="#consoleerrordata-args"><code>console.error([data][, ...args])</code></a></li>
313<li><a href="#consolegrouplabel"><code>console.group([...label])</code></a></li>
314<li><a href="#consolegroupcollapsed"><code>console.groupCollapsed()</code></a></li>
315<li><a href="#consolegroupend"><code>console.groupEnd()</code></a></li>
316<li><a href="#consoleinfodata-args"><code>console.info([data][, ...args])</code></a></li>
317<li><a href="#consolelogdata-args"><code>console.log([data][, ...args])</code></a></li>
318<li><a href="#consoletabletabulardata-properties"><code>console.table(tabularData[, properties])</code></a></li>
319<li><a href="#consoletimelabel"><code>console.time([label])</code></a></li>
320<li><a href="#consoletimeendlabel"><code>console.timeEnd([label])</code></a></li>
321<li><a href="#consoletimeloglabel-data"><code>console.timeLog([label][, ...data])</code></a></li>
322<li><a href="#consoletracemessage-args"><code>console.trace([message][, ...args])</code></a></li>
323<li><a href="#consolewarndata-args"><code>console.warn([data][, ...args])</code></a></li>
324</ul>
325</li>
326<li><a href="#inspector-only-methods">Inspector only methods</a>
327<ul>
328<li><a href="#consoleprofilelabel"><code>console.profile([label])</code></a></li>
329<li><a href="#consoleprofileendlabel"><code>console.profileEnd([label])</code></a></li>
330<li><a href="#consoletimestamplabel"><code>console.timeStamp([label])</code></a></li>
331</ul>
332</li>
333</ul>
334</li>
335</ul></details>
336
337      <div id="apicontent">
338        <h2>Console<span><a class="mark" href="#console" id="console">#</a></span><a aria-hidden="true" class="legacy" id="console_console"></a></h2>
339
340<p></p><div class="api_stability api_stability_2"><a href="documentation.html#stability-index">Stability: 2</a> - Stable</div><p></p>
341<p><strong>Source Code:</strong> <a href="https://github.com/nodejs/node/blob/v18.20.1/lib/console.js">lib/console.js</a></p>
342<p>The <code>node:console</code> module provides a simple debugging console that is similar to
343the JavaScript console mechanism provided by web browsers.</p>
344<p>The module exports two specific components:</p>
345<ul>
346<li>A <code>Console</code> class with methods such as <code>console.log()</code>, <code>console.error()</code>, and
347<code>console.warn()</code> that can be used to write to any Node.js stream.</li>
348<li>A global <code>console</code> instance configured to write to <a href="process.html#processstdout"><code>process.stdout</code></a> and
349<a href="process.html#processstderr"><code>process.stderr</code></a>. The global <code>console</code> can be used without calling
350<code>require('node:console')</code>.</li>
351</ul>
352<p><em><strong>Warning</strong></em>: The global console object's methods are neither consistently
353synchronous like the browser APIs they resemble, nor are they consistently
354asynchronous like all other Node.js streams. See the <a href="process.html#a-note-on-process-io">note on process I/O</a> for
355more information.</p>
356<p>Example using the global <code>console</code>:</p>
357<pre><code class="language-js"><span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(<span class="hljs-string">'hello world'</span>);
358<span class="hljs-comment">// Prints: hello world, to stdout</span>
359<span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(<span class="hljs-string">'hello %s'</span>, <span class="hljs-string">'world'</span>);
360<span class="hljs-comment">// Prints: hello world, to stdout</span>
361<span class="hljs-variable language_">console</span>.<span class="hljs-title function_">error</span>(<span class="hljs-keyword">new</span> <span class="hljs-title class_">Error</span>(<span class="hljs-string">'Whoops, something bad happened'</span>));
362<span class="hljs-comment">// Prints error message and stack trace to stderr:</span>
363<span class="hljs-comment">//   Error: Whoops, something bad happened</span>
364<span class="hljs-comment">//     at [eval]:5:15</span>
365<span class="hljs-comment">//     at Script.runInThisContext (node:vm:132:18)</span>
366<span class="hljs-comment">//     at Object.runInThisContext (node:vm:309:38)</span>
367<span class="hljs-comment">//     at node:internal/process/execution:77:19</span>
368<span class="hljs-comment">//     at [eval]-wrapper:6:22</span>
369<span class="hljs-comment">//     at evalScript (node:internal/process/execution:76:60)</span>
370<span class="hljs-comment">//     at node:internal/main/eval_string:23:3</span>
371
372<span class="hljs-keyword">const</span> name = <span class="hljs-string">'Will Robinson'</span>;
373<span class="hljs-variable language_">console</span>.<span class="hljs-title function_">warn</span>(<span class="hljs-string">`Danger <span class="hljs-subst">${name}</span>! Danger!`</span>);
374<span class="hljs-comment">// Prints: Danger Will Robinson! Danger!, to stderr</span></code> <button class="copy-button">copy</button></pre>
375<p>Example using the <code>Console</code> class:</p>
376<pre><code class="language-js"><span class="hljs-keyword">const</span> out = <span class="hljs-title function_">getStreamSomehow</span>();
377<span class="hljs-keyword">const</span> err = <span class="hljs-title function_">getStreamSomehow</span>();
378<span class="hljs-keyword">const</span> myConsole = <span class="hljs-keyword">new</span> <span class="hljs-variable language_">console</span>.<span class="hljs-title class_">Console</span>(out, err);
379
380myConsole.<span class="hljs-title function_">log</span>(<span class="hljs-string">'hello world'</span>);
381<span class="hljs-comment">// Prints: hello world, to out</span>
382myConsole.<span class="hljs-title function_">log</span>(<span class="hljs-string">'hello %s'</span>, <span class="hljs-string">'world'</span>);
383<span class="hljs-comment">// Prints: hello world, to out</span>
384myConsole.<span class="hljs-title function_">error</span>(<span class="hljs-keyword">new</span> <span class="hljs-title class_">Error</span>(<span class="hljs-string">'Whoops, something bad happened'</span>));
385<span class="hljs-comment">// Prints: [Error: Whoops, something bad happened], to err</span>
386
387<span class="hljs-keyword">const</span> name = <span class="hljs-string">'Will Robinson'</span>;
388myConsole.<span class="hljs-title function_">warn</span>(<span class="hljs-string">`Danger <span class="hljs-subst">${name}</span>! Danger!`</span>);
389<span class="hljs-comment">// Prints: Danger Will Robinson! Danger!, to err</span></code> <button class="copy-button">copy</button></pre>
390<section><h3>Class: <code>Console</code><span><a class="mark" href="#class-console" id="class-console">#</a></span><a aria-hidden="true" class="legacy" id="console_class_console"></a></h3>
391<div class="api_metadata">
392<details class="changelog"><summary>History</summary>
393<table>
394<tbody><tr><th>Version</th><th>Changes</th></tr>
395<tr><td>v8.0.0</td>
396<td><p>Errors that occur while writing to the underlying streams will now be ignored by default.</p></td></tr>
397</tbody></table>
398</details>
399</div>
400
401<p>The <code>Console</code> class can be used to create a simple logger with configurable
402output streams and can be accessed using either <code>require('node:console').Console</code>
403or <code>console.Console</code> (or their destructured counterparts):</p>
404<pre><code class="language-js"><span class="hljs-keyword">const</span> { <span class="hljs-title class_">Console</span> } = <span class="hljs-built_in">require</span>(<span class="hljs-string">'node:console'</span>);</code> <button class="copy-button">copy</button></pre>
405<pre><code class="language-js"><span class="hljs-keyword">const</span> { <span class="hljs-title class_">Console</span> } = <span class="hljs-variable language_">console</span>;</code> <button class="copy-button">copy</button></pre>
406<h4><code>new Console(stdout[, stderr][, ignoreErrors])</code><span><a class="mark" href="#new-consolestdout-stderr-ignoreerrors" id="new-consolestdout-stderr-ignoreerrors">#</a></span><a aria-hidden="true" class="legacy" id="console_new_console_stdout_stderr_ignoreerrors"></a></h4>
407<h4><code>new Console(options)</code><span><a class="mark" href="#new-consoleoptions" id="new-consoleoptions">#</a></span><a aria-hidden="true" class="legacy" id="console_new_console_options"></a></h4>
408<div class="api_metadata">
409<details class="changelog"><summary>History</summary>
410<table>
411<tbody><tr><th>Version</th><th>Changes</th></tr>
412<tr><td>v14.2.0, v12.17.0</td>
413<td><p>The <code>groupIndentation</code> option was introduced.</p></td></tr>
414<tr><td>v11.7.0</td>
415<td><p>The <code>inspectOptions</code> option is introduced.</p></td></tr>
416<tr><td>v10.0.0</td>
417<td><p>The <code>Console</code> constructor now supports an <code>options</code> argument, and the <code>colorMode</code> option was introduced.</p></td></tr>
418<tr><td>v8.0.0</td>
419<td><p>The <code>ignoreErrors</code> option was introduced.</p></td></tr>
420</tbody></table>
421</details>
422</div>
423<ul>
424<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a>
425<ul>
426<li><code>stdout</code> <a href="stream.html#class-streamwritable" class="type">&#x3C;stream.Writable></a></li>
427<li><code>stderr</code> <a href="stream.html#class-streamwritable" class="type">&#x3C;stream.Writable></a></li>
428<li><code>ignoreErrors</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type">&#x3C;boolean></a> Ignore errors when writing to the underlying
429streams. <strong>Default:</strong> <code>true</code>.</li>
430<li><code>colorMode</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type">&#x3C;boolean></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> Set color support for this <code>Console</code> instance.
431Setting to <code>true</code> enables coloring while inspecting values. Setting to
432<code>false</code> disables coloring while inspecting values. Setting to
433<code>'auto'</code> makes color support depend on the value of the <code>isTTY</code> property
434and the value returned by <code>getColorDepth()</code> on the respective stream. This
435option can not be used, if <code>inspectOptions.colors</code> is set as well.
436<strong>Default:</strong> <code>'auto'</code>.</li>
437<li><code>inspectOptions</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a> Specifies options that are passed along to
438<a href="util.html#utilinspectobject-options"><code>util.inspect()</code></a>.</li>
439<li><code>groupIndentation</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> Set group indentation.
440<strong>Default:</strong> <code>2</code>.</li>
441</ul>
442</li>
443</ul>
444<p>Creates a new <code>Console</code> with one or two writable stream instances. <code>stdout</code> is a
445writable stream to print log or info output. <code>stderr</code> is used for warning or
446error output. If <code>stderr</code> is not provided, <code>stdout</code> is used for <code>stderr</code>.</p>
447<pre><code class="language-js"><span class="hljs-keyword">const</span> output = fs.<span class="hljs-title function_">createWriteStream</span>(<span class="hljs-string">'./stdout.log'</span>);
448<span class="hljs-keyword">const</span> errorOutput = fs.<span class="hljs-title function_">createWriteStream</span>(<span class="hljs-string">'./stderr.log'</span>);
449<span class="hljs-comment">// Custom simple logger</span>
450<span class="hljs-keyword">const</span> logger = <span class="hljs-keyword">new</span> <span class="hljs-title class_">Console</span>({ <span class="hljs-attr">stdout</span>: output, <span class="hljs-attr">stderr</span>: errorOutput });
451<span class="hljs-comment">// use it like console</span>
452<span class="hljs-keyword">const</span> count = <span class="hljs-number">5</span>;
453logger.<span class="hljs-title function_">log</span>(<span class="hljs-string">'count: %d'</span>, count);
454<span class="hljs-comment">// In stdout.log: count 5</span></code> <button class="copy-button">copy</button></pre>
455<p>The global <code>console</code> is a special <code>Console</code> whose output is sent to
456<a href="process.html#processstdout"><code>process.stdout</code></a> and <a href="process.html#processstderr"><code>process.stderr</code></a>. It is equivalent to calling:</p>
457<pre><code class="language-js"><span class="hljs-keyword">new</span> <span class="hljs-title class_">Console</span>({ <span class="hljs-attr">stdout</span>: process.<span class="hljs-property">stdout</span>, <span class="hljs-attr">stderr</span>: process.<span class="hljs-property">stderr</span> });</code> <button class="copy-button">copy</button></pre>
458<h4><code>console.assert(value[, ...message])</code><span><a class="mark" href="#consoleassertvalue-message" id="consoleassertvalue-message">#</a></span><a aria-hidden="true" class="legacy" id="console_console_assert_value_message"></a></h4>
459<div class="api_metadata">
460<details class="changelog"><summary>History</summary>
461<table>
462<tbody><tr><th>Version</th><th>Changes</th></tr>
463<tr><td>v10.0.0</td>
464<td><p>The implementation is now spec compliant and does not throw anymore.</p></td></tr>
465<tr><td>v0.1.101</td>
466<td><p><span>Added in: v0.1.101</span></p></td></tr>
467</tbody></table>
468</details>
469</div>
470<ul>
471<li><code>value</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type">&#x3C;any></a> The value tested for being truthy.</li>
472<li><code>...message</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type">&#x3C;any></a> All arguments besides <code>value</code> are used as error message.</li>
473</ul>
474<p><code>console.assert()</code> writes a message if <code>value</code> is <a href="https://developer.mozilla.org/en-US/docs/Glossary/Falsy">falsy</a> or omitted. It only
475writes a message and does not otherwise affect execution. The output always
476starts with <code>"Assertion failed"</code>. If provided, <code>message</code> is formatted using
477<a href="util.html#utilformatformat-args"><code>util.format()</code></a>.</p>
478<p>If <code>value</code> is <a href="https://developer.mozilla.org/en-US/docs/Glossary/Truthy">truthy</a>, nothing happens.</p>
479<pre><code class="language-js"><span class="hljs-variable language_">console</span>.<span class="hljs-title function_">assert</span>(<span class="hljs-literal">true</span>, <span class="hljs-string">'does nothing'</span>);
480
481<span class="hljs-variable language_">console</span>.<span class="hljs-title function_">assert</span>(<span class="hljs-literal">false</span>, <span class="hljs-string">'Whoops %s work'</span>, <span class="hljs-string">'didn\'t'</span>);
482<span class="hljs-comment">// Assertion failed: Whoops didn't work</span>
483
484<span class="hljs-variable language_">console</span>.<span class="hljs-title function_">assert</span>();
485<span class="hljs-comment">// Assertion failed</span></code> <button class="copy-button">copy</button></pre>
486<h4><code>console.clear()</code><span><a class="mark" href="#consoleclear" id="consoleclear">#</a></span><a aria-hidden="true" class="legacy" id="console_console_clear"></a></h4>
487<div class="api_metadata">
488<span>Added in: v8.3.0</span>
489</div>
490<p>When <code>stdout</code> is a TTY, calling <code>console.clear()</code> will attempt to clear the
491TTY. When <code>stdout</code> is not a TTY, this method does nothing.</p>
492<p>The specific operation of <code>console.clear()</code> can vary across operating systems
493and terminal types. For most Linux operating systems, <code>console.clear()</code>
494operates similarly to the <code>clear</code> shell command. On Windows, <code>console.clear()</code>
495will clear only the output in the current terminal viewport for the Node.js
496binary.</p>
497<h4><code>console.count([label])</code><span><a class="mark" href="#consolecountlabel" id="consolecountlabel">#</a></span><a aria-hidden="true" class="legacy" id="console_console_count_label"></a></h4>
498<div class="api_metadata">
499<span>Added in: v8.3.0</span>
500</div>
501<ul>
502<li><code>label</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> The display label for the counter. <strong>Default:</strong> <code>'default'</code>.</li>
503</ul>
504<p>Maintains an internal counter specific to <code>label</code> and outputs to <code>stdout</code> the
505number of times <code>console.count()</code> has been called with the given <code>label</code>.</p>
506<!-- eslint-skip -->
507<pre><code class="language-js">> <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">count</span>()
508<span class="hljs-attr">default</span>: <span class="hljs-number">1</span>
509<span class="hljs-literal">undefined</span>
510> <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">count</span>(<span class="hljs-string">'default'</span>)
511<span class="hljs-attr">default</span>: <span class="hljs-number">2</span>
512<span class="hljs-literal">undefined</span>
513> <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">count</span>(<span class="hljs-string">'abc'</span>)
514<span class="hljs-attr">abc</span>: <span class="hljs-number">1</span>
515<span class="hljs-literal">undefined</span>
516> <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">count</span>(<span class="hljs-string">'xyz'</span>)
517<span class="hljs-attr">xyz</span>: <span class="hljs-number">1</span>
518<span class="hljs-literal">undefined</span>
519> <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">count</span>(<span class="hljs-string">'abc'</span>)
520<span class="hljs-attr">abc</span>: <span class="hljs-number">2</span>
521<span class="hljs-literal">undefined</span>
522> <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">count</span>()
523<span class="hljs-attr">default</span>: <span class="hljs-number">3</span>
524<span class="hljs-literal">undefined</span>
525></code> <button class="copy-button">copy</button></pre>
526<h4><code>console.countReset([label])</code><span><a class="mark" href="#consolecountresetlabel" id="consolecountresetlabel">#</a></span><a aria-hidden="true" class="legacy" id="console_console_countreset_label"></a></h4>
527<div class="api_metadata">
528<span>Added in: v8.3.0</span>
529</div>
530<ul>
531<li><code>label</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> The display label for the counter. <strong>Default:</strong> <code>'default'</code>.</li>
532</ul>
533<p>Resets the internal counter specific to <code>label</code>.</p>
534<!-- eslint-skip -->
535<pre><code class="language-js">> <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">count</span>(<span class="hljs-string">'abc'</span>);
536<span class="hljs-attr">abc</span>: <span class="hljs-number">1</span>
537<span class="hljs-literal">undefined</span>
538> <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">countReset</span>(<span class="hljs-string">'abc'</span>);
539<span class="hljs-literal">undefined</span>
540> <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">count</span>(<span class="hljs-string">'abc'</span>);
541<span class="hljs-attr">abc</span>: <span class="hljs-number">1</span>
542<span class="hljs-literal">undefined</span>
543></code> <button class="copy-button">copy</button></pre>
544<h4><code>console.debug(data[, ...args])</code><span><a class="mark" href="#consoledebugdata-args" id="consoledebugdata-args">#</a></span><a aria-hidden="true" class="legacy" id="console_console_debug_data_args"></a></h4>
545<div class="api_metadata">
546<details class="changelog"><summary>History</summary>
547<table>
548<tbody><tr><th>Version</th><th>Changes</th></tr>
549<tr><td>v8.10.0</td>
550<td><p><code>console.debug</code> is now an alias for <code>console.log</code>.</p></td></tr>
551<tr><td>v8.0.0</td>
552<td><p><span>Added in: v8.0.0</span></p></td></tr>
553</tbody></table>
554</details>
555</div>
556<ul>
557<li><code>data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type">&#x3C;any></a></li>
558<li><code>...args</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type">&#x3C;any></a></li>
559</ul>
560<p>The <code>console.debug()</code> function is an alias for <a href="#consolelogdata-args"><code>console.log()</code></a>.</p>
561<h4><code>console.dir(obj[, options])</code><span><a class="mark" href="#consoledirobj-options" id="consoledirobj-options">#</a></span><a aria-hidden="true" class="legacy" id="console_console_dir_obj_options"></a></h4>
562<div class="api_metadata">
563<span>Added in: v0.1.101</span>
564</div>
565<ul>
566<li><code>obj</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type">&#x3C;any></a></li>
567<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type">&#x3C;Object></a>
568<ul>
569<li><code>showHidden</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type">&#x3C;boolean></a> If <code>true</code> then the object's non-enumerable and symbol
570properties will be shown too. <strong>Default:</strong> <code>false</code>.</li>
571<li><code>depth</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type">&#x3C;number></a> Tells <a href="util.html#utilinspectobject-options"><code>util.inspect()</code></a> how many times to recurse while
572formatting the object. This is useful for inspecting large complicated
573objects. To make it recurse indefinitely, pass <code>null</code>. <strong>Default:</strong> <code>2</code>.</li>
574<li><code>colors</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type">&#x3C;boolean></a> If <code>true</code>, then the output will be styled with ANSI color
575codes. Colors are customizable;
576see <a href="util.html#customizing-utilinspect-colors">customizing <code>util.inspect()</code> colors</a>. <strong>Default:</strong> <code>false</code>.</li>
577</ul>
578</li>
579</ul>
580<p>Uses <a href="util.html#utilinspectobject-options"><code>util.inspect()</code></a> on <code>obj</code> and prints the resulting string to <code>stdout</code>.
581This function bypasses any custom <code>inspect()</code> function defined on <code>obj</code>.</p>
582<h4><code>console.dirxml(...data)</code><span><a class="mark" href="#consoledirxmldata" id="consoledirxmldata">#</a></span><a aria-hidden="true" class="legacy" id="console_console_dirxml_data"></a></h4>
583<div class="api_metadata">
584<details class="changelog"><summary>History</summary>
585<table>
586<tbody><tr><th>Version</th><th>Changes</th></tr>
587<tr><td>v9.3.0</td>
588<td><p><code>console.dirxml</code> now calls <code>console.log</code> for its arguments.</p></td></tr>
589<tr><td>v8.0.0</td>
590<td><p><span>Added in: v8.0.0</span></p></td></tr>
591</tbody></table>
592</details>
593</div>
594<ul>
595<li><code>...data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type">&#x3C;any></a></li>
596</ul>
597<p>This method calls <code>console.log()</code> passing it the arguments received.
598This method does not produce any XML formatting.</p>
599<h4><code>console.error([data][, ...args])</code><span><a class="mark" href="#consoleerrordata-args" id="consoleerrordata-args">#</a></span><a aria-hidden="true" class="legacy" id="console_console_error_data_args"></a></h4>
600<div class="api_metadata">
601<span>Added in: v0.1.100</span>
602</div>
603<ul>
604<li><code>data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type">&#x3C;any></a></li>
605<li><code>...args</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type">&#x3C;any></a></li>
606</ul>
607<p>Prints to <code>stderr</code> with newline. Multiple arguments can be passed, with the
608first used as the primary message and all additional used as substitution
609values similar to <a href="http://man7.org/linux/man-pages/man3/printf.3.html"><code>printf(3)</code></a> (the arguments are all passed to
610<a href="util.html#utilformatformat-args"><code>util.format()</code></a>).</p>
611<pre><code class="language-js"><span class="hljs-keyword">const</span> code = <span class="hljs-number">5</span>;
612<span class="hljs-variable language_">console</span>.<span class="hljs-title function_">error</span>(<span class="hljs-string">'error #%d'</span>, code);
613<span class="hljs-comment">// Prints: error #5, to stderr</span>
614<span class="hljs-variable language_">console</span>.<span class="hljs-title function_">error</span>(<span class="hljs-string">'error'</span>, code);
615<span class="hljs-comment">// Prints: error 5, to stderr</span></code> <button class="copy-button">copy</button></pre>
616<p>If formatting elements (e.g. <code>%d</code>) are not found in the first string then
617<a href="util.html#utilinspectobject-options"><code>util.inspect()</code></a> is called on each argument and the resulting string
618values are concatenated. See <a href="util.html#utilformatformat-args"><code>util.format()</code></a> for more information.</p>
619<h4><code>console.group([...label])</code><span><a class="mark" href="#consolegrouplabel" id="consolegrouplabel">#</a></span><a aria-hidden="true" class="legacy" id="console_console_group_label"></a></h4>
620<div class="api_metadata">
621<span>Added in: v8.5.0</span>
622</div>
623<ul>
624<li><code>...label</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type">&#x3C;any></a></li>
625</ul>
626<p>Increases indentation of subsequent lines by spaces for <code>groupIndentation</code>
627length.</p>
628<p>If one or more <code>label</code>s are provided, those are printed first without the
629additional indentation.</p>
630<h4><code>console.groupCollapsed()</code><span><a class="mark" href="#consolegroupcollapsed" id="consolegroupcollapsed">#</a></span><a aria-hidden="true" class="legacy" id="console_console_groupcollapsed"></a></h4>
631<div class="api_metadata">
632<span>Added in: v8.5.0</span>
633</div>
634<p>An alias for <a href="#consolegrouplabel"><code>console.group()</code></a>.</p>
635<h4><code>console.groupEnd()</code><span><a class="mark" href="#consolegroupend" id="consolegroupend">#</a></span><a aria-hidden="true" class="legacy" id="console_console_groupend"></a></h4>
636<div class="api_metadata">
637<span>Added in: v8.5.0</span>
638</div>
639<p>Decreases indentation of subsequent lines by spaces for <code>groupIndentation</code>
640length.</p>
641<h4><code>console.info([data][, ...args])</code><span><a class="mark" href="#consoleinfodata-args" id="consoleinfodata-args">#</a></span><a aria-hidden="true" class="legacy" id="console_console_info_data_args"></a></h4>
642<div class="api_metadata">
643<span>Added in: v0.1.100</span>
644</div>
645<ul>
646<li><code>data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type">&#x3C;any></a></li>
647<li><code>...args</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type">&#x3C;any></a></li>
648</ul>
649<p>The <code>console.info()</code> function is an alias for <a href="#consolelogdata-args"><code>console.log()</code></a>.</p>
650<h4><code>console.log([data][, ...args])</code><span><a class="mark" href="#consolelogdata-args" id="consolelogdata-args">#</a></span><a aria-hidden="true" class="legacy" id="console_console_log_data_args"></a></h4>
651<div class="api_metadata">
652<span>Added in: v0.1.100</span>
653</div>
654<ul>
655<li><code>data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type">&#x3C;any></a></li>
656<li><code>...args</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type">&#x3C;any></a></li>
657</ul>
658<p>Prints to <code>stdout</code> with newline. Multiple arguments can be passed, with the
659first used as the primary message and all additional used as substitution
660values similar to <a href="http://man7.org/linux/man-pages/man3/printf.3.html"><code>printf(3)</code></a> (the arguments are all passed to
661<a href="util.html#utilformatformat-args"><code>util.format()</code></a>).</p>
662<pre><code class="language-js"><span class="hljs-keyword">const</span> count = <span class="hljs-number">5</span>;
663<span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(<span class="hljs-string">'count: %d'</span>, count);
664<span class="hljs-comment">// Prints: count: 5, to stdout</span>
665<span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(<span class="hljs-string">'count:'</span>, count);
666<span class="hljs-comment">// Prints: count: 5, to stdout</span></code> <button class="copy-button">copy</button></pre>
667<p>See <a href="util.html#utilformatformat-args"><code>util.format()</code></a> for more information.</p>
668<h4><code>console.table(tabularData[, properties])</code><span><a class="mark" href="#consoletabletabulardata-properties" id="consoletabletabulardata-properties">#</a></span><a aria-hidden="true" class="legacy" id="console_console_table_tabulardata_properties"></a></h4>
669<div class="api_metadata">
670<span>Added in: v10.0.0</span>
671</div>
672<ul>
673<li><code>tabularData</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type">&#x3C;any></a></li>
674<li><code>properties</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string[]></a> Alternate properties for constructing the table.</li>
675</ul>
676<p>Try to construct a table with the columns of the properties of <code>tabularData</code>
677(or use <code>properties</code>) and rows of <code>tabularData</code> and log it. Falls back to just
678logging the argument if it can't be parsed as tabular.</p>
679<pre><code class="language-js"><span class="hljs-comment">// These can't be parsed as tabular data</span>
680<span class="hljs-variable language_">console</span>.<span class="hljs-title function_">table</span>(<span class="hljs-title class_">Symbol</span>());
681<span class="hljs-comment">// Symbol()</span>
682
683<span class="hljs-variable language_">console</span>.<span class="hljs-title function_">table</span>(<span class="hljs-literal">undefined</span>);
684<span class="hljs-comment">// undefined</span>
685
686<span class="hljs-variable language_">console</span>.<span class="hljs-title function_">table</span>([{ <span class="hljs-attr">a</span>: <span class="hljs-number">1</span>, <span class="hljs-attr">b</span>: <span class="hljs-string">'Y'</span> }, { <span class="hljs-attr">a</span>: <span class="hljs-string">'Z'</span>, <span class="hljs-attr">b</span>: <span class="hljs-number">2</span> }]);
687<span class="hljs-comment">// ┌─────────┬─────┬─────┐</span>
688<span class="hljs-comment">// │ (index) │  a  │  b  │</span>
689<span class="hljs-comment">// ├─────────┼─────┼─────┤</span>
690<span class="hljs-comment">// │    0    │  1  │ 'Y' │</span>
691<span class="hljs-comment">// │    1    │ 'Z' │  2  │</span>
692<span class="hljs-comment">// └─────────┴─────┴─────┘</span>
693
694<span class="hljs-variable language_">console</span>.<span class="hljs-title function_">table</span>([{ <span class="hljs-attr">a</span>: <span class="hljs-number">1</span>, <span class="hljs-attr">b</span>: <span class="hljs-string">'Y'</span> }, { <span class="hljs-attr">a</span>: <span class="hljs-string">'Z'</span>, <span class="hljs-attr">b</span>: <span class="hljs-number">2</span> }], [<span class="hljs-string">'a'</span>]);
695<span class="hljs-comment">// ┌─────────┬─────┐</span>
696<span class="hljs-comment">// │ (index) │  a  │</span>
697<span class="hljs-comment">// ├─────────┼─────┤</span>
698<span class="hljs-comment">// │    0    │  1  │</span>
699<span class="hljs-comment">// │    1    │ 'Z' │</span>
700<span class="hljs-comment">// └─────────┴─────┘</span></code> <button class="copy-button">copy</button></pre>
701<h4><code>console.time([label])</code><span><a class="mark" href="#consoletimelabel" id="consoletimelabel">#</a></span><a aria-hidden="true" class="legacy" id="console_console_time_label"></a></h4>
702<div class="api_metadata">
703<span>Added in: v0.1.104</span>
704</div>
705<ul>
706<li><code>label</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> <strong>Default:</strong> <code>'default'</code></li>
707</ul>
708<p>Starts a timer that can be used to compute the duration of an operation. Timers
709are identified by a unique <code>label</code>. Use the same <code>label</code> when calling
710<a href="#consoletimeendlabel"><code>console.timeEnd()</code></a> to stop the timer and output the elapsed time in
711suitable time units to <code>stdout</code>. For example, if the elapsed
712time is 3869ms, <code>console.timeEnd()</code> displays "3.869s".</p>
713<h4><code>console.timeEnd([label])</code><span><a class="mark" href="#consoletimeendlabel" id="consoletimeendlabel">#</a></span><a aria-hidden="true" class="legacy" id="console_console_timeend_label"></a></h4>
714<div class="api_metadata">
715<details class="changelog"><summary>History</summary>
716<table>
717<tbody><tr><th>Version</th><th>Changes</th></tr>
718<tr><td>v13.0.0</td>
719<td><p>The elapsed time is displayed with a suitable time unit.</p></td></tr>
720<tr><td>v6.0.0</td>
721<td><p>This method no longer supports multiple calls that don't map to individual <code>console.time()</code> calls; see below for details.</p></td></tr>
722<tr><td>v0.1.104</td>
723<td><p><span>Added in: v0.1.104</span></p></td></tr>
724</tbody></table>
725</details>
726</div>
727<ul>
728<li><code>label</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> <strong>Default:</strong> <code>'default'</code></li>
729</ul>
730<p>Stops a timer that was previously started by calling <a href="#consoletimelabel"><code>console.time()</code></a> and
731prints the result to <code>stdout</code>:</p>
732<pre><code class="language-js"><span class="hljs-variable language_">console</span>.<span class="hljs-title function_">time</span>(<span class="hljs-string">'bunch-of-stuff'</span>);
733<span class="hljs-comment">// Do a bunch of stuff.</span>
734<span class="hljs-variable language_">console</span>.<span class="hljs-title function_">timeEnd</span>(<span class="hljs-string">'bunch-of-stuff'</span>);
735<span class="hljs-comment">// Prints: bunch-of-stuff: 225.438ms</span></code> <button class="copy-button">copy</button></pre>
736<h4><code>console.timeLog([label][, ...data])</code><span><a class="mark" href="#consoletimeloglabel-data" id="consoletimeloglabel-data">#</a></span><a aria-hidden="true" class="legacy" id="console_console_timelog_label_data"></a></h4>
737<div class="api_metadata">
738<span>Added in: v10.7.0</span>
739</div>
740<ul>
741<li><code>label</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a> <strong>Default:</strong> <code>'default'</code></li>
742<li><code>...data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type">&#x3C;any></a></li>
743</ul>
744<p>For a timer that was previously started by calling <a href="#consoletimelabel"><code>console.time()</code></a>, prints
745the elapsed time and other <code>data</code> arguments to <code>stdout</code>:</p>
746<pre><code class="language-js"><span class="hljs-variable language_">console</span>.<span class="hljs-title function_">time</span>(<span class="hljs-string">'process'</span>);
747<span class="hljs-keyword">const</span> value = <span class="hljs-title function_">expensiveProcess1</span>(); <span class="hljs-comment">// Returns 42</span>
748<span class="hljs-variable language_">console</span>.<span class="hljs-title function_">timeLog</span>(<span class="hljs-string">'process'</span>, value);
749<span class="hljs-comment">// Prints "process: 365.227ms 42".</span>
750<span class="hljs-title function_">doExpensiveProcess2</span>(value);
751<span class="hljs-variable language_">console</span>.<span class="hljs-title function_">timeEnd</span>(<span class="hljs-string">'process'</span>);</code> <button class="copy-button">copy</button></pre>
752<h4><code>console.trace([message][, ...args])</code><span><a class="mark" href="#consoletracemessage-args" id="consoletracemessage-args">#</a></span><a aria-hidden="true" class="legacy" id="console_console_trace_message_args"></a></h4>
753<div class="api_metadata">
754<span>Added in: v0.1.104</span>
755</div>
756<ul>
757<li><code>message</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type">&#x3C;any></a></li>
758<li><code>...args</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type">&#x3C;any></a></li>
759</ul>
760<p>Prints to <code>stderr</code> the string <code>'Trace: '</code>, followed by the <a href="util.html#utilformatformat-args"><code>util.format()</code></a>
761formatted message and stack trace to the current position in the code.</p>
762<pre><code class="language-js"><span class="hljs-variable language_">console</span>.<span class="hljs-title function_">trace</span>(<span class="hljs-string">'Show me'</span>);
763<span class="hljs-comment">// Prints: (stack trace will vary based on where trace is called)</span>
764<span class="hljs-comment">//  Trace: Show me</span>
765<span class="hljs-comment">//    at repl:2:9</span>
766<span class="hljs-comment">//    at REPLServer.defaultEval (repl.js:248:27)</span>
767<span class="hljs-comment">//    at bound (domain.js:287:14)</span>
768<span class="hljs-comment">//    at REPLServer.runBound [as eval] (domain.js:300:12)</span>
769<span class="hljs-comment">//    at REPLServer.&#x3C;anonymous> (repl.js:412:12)</span>
770<span class="hljs-comment">//    at emitOne (events.js:82:20)</span>
771<span class="hljs-comment">//    at REPLServer.emit (events.js:169:7)</span>
772<span class="hljs-comment">//    at REPLServer.Interface._onLine (readline.js:210:10)</span>
773<span class="hljs-comment">//    at REPLServer.Interface._line (readline.js:549:8)</span>
774<span class="hljs-comment">//    at REPLServer.Interface._ttyWrite (readline.js:826:14)</span></code> <button class="copy-button">copy</button></pre>
775<h4><code>console.warn([data][, ...args])</code><span><a class="mark" href="#consolewarndata-args" id="consolewarndata-args">#</a></span><a aria-hidden="true" class="legacy" id="console_console_warn_data_args"></a></h4>
776<div class="api_metadata">
777<span>Added in: v0.1.100</span>
778</div>
779<ul>
780<li><code>data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type">&#x3C;any></a></li>
781<li><code>...args</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type">&#x3C;any></a></li>
782</ul>
783<p>The <code>console.warn()</code> function is an alias for <a href="#consoleerrordata-args"><code>console.error()</code></a>.</p>
784</section><section><h3>Inspector only methods<span><a class="mark" href="#inspector-only-methods" id="inspector-only-methods">#</a></span><a aria-hidden="true" class="legacy" id="console_inspector_only_methods"></a></h3>
785<p>The following methods are exposed by the V8 engine in the general API but do
786not display anything unless used in conjunction with the <a href="debugger.html">inspector</a>
787(<code>--inspect</code> flag).</p>
788<h4><code>console.profile([label])</code><span><a class="mark" href="#consoleprofilelabel" id="consoleprofilelabel">#</a></span><a aria-hidden="true" class="legacy" id="console_console_profile_label"></a></h4>
789<div class="api_metadata">
790<span>Added in: v8.0.0</span>
791</div>
792<ul>
793<li><code>label</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a></li>
794</ul>
795<p>This method does not display anything unless used in the inspector. The
796<code>console.profile()</code> method starts a JavaScript CPU profile with an optional
797label until <a href="#consoleprofileendlabel"><code>console.profileEnd()</code></a> is called. The profile is then added to
798the <strong>Profile</strong> panel of the inspector.</p>
799<pre><code class="language-js"><span class="hljs-variable language_">console</span>.<span class="hljs-title function_">profile</span>(<span class="hljs-string">'MyLabel'</span>);
800<span class="hljs-comment">// Some code</span>
801<span class="hljs-variable language_">console</span>.<span class="hljs-title function_">profileEnd</span>(<span class="hljs-string">'MyLabel'</span>);
802<span class="hljs-comment">// Adds the profile 'MyLabel' to the Profiles panel of the inspector.</span></code> <button class="copy-button">copy</button></pre>
803<h4><code>console.profileEnd([label])</code><span><a class="mark" href="#consoleprofileendlabel" id="consoleprofileendlabel">#</a></span><a aria-hidden="true" class="legacy" id="console_console_profileend_label"></a></h4>
804<div class="api_metadata">
805<span>Added in: v8.0.0</span>
806</div>
807<ul>
808<li><code>label</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a></li>
809</ul>
810<p>This method does not display anything unless used in the inspector. Stops the
811current JavaScript CPU profiling session if one has been started and prints
812the report to the <strong>Profiles</strong> panel of the inspector. See
813<a href="#consoleprofilelabel"><code>console.profile()</code></a> for an example.</p>
814<p>If this method is called without a label, the most recently started profile is
815stopped.</p>
816<h4><code>console.timeStamp([label])</code><span><a class="mark" href="#consoletimestamplabel" id="consoletimestamplabel">#</a></span><a aria-hidden="true" class="legacy" id="console_console_timestamp_label"></a></h4>
817<div class="api_metadata">
818<span>Added in: v8.0.0</span>
819</div>
820<ul>
821<li><code>label</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type">&#x3C;string></a></li>
822</ul>
823<p>This method does not display anything unless used in the inspector. The
824<code>console.timeStamp()</code> method adds an event with the label <code>'label'</code> to the
825<strong>Timeline</strong> panel of the inspector.</p></section>
826        <!-- API END -->
827      </div>
828    </div>
829  </div>
830</body>
831</html>
832