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<h2>Table of Contents</h2>
<ul>
<li>
<p><span class="stability_2"><a href="#console_console">Console</a></span></p>
<ul>
<li>
<p><a href="#console_class_console">Class: <code>Console</code></a></p>
<ul>
<li><a href="#console_new_console_stdout_stderr_ignoreerrors"><code>new Console(stdout[, stderr][, ignoreErrors])</code></a></li>
<li><a href="#console_new_console_options"><code>new Console(options)</code></a></li>
<li><a href="#console_console_assert_value_message"><code>console.assert(value[, ...message])</code></a></li>
<li><a href="#console_console_clear"><code>console.clear()</code></a></li>
<li><a href="#console_console_count_label"><code>console.count([label])</code></a></li>
<li><a href="#console_console_countreset_label"><code>console.countReset([label])</code></a></li>
<li><a href="#console_console_debug_data_args"><code>console.debug(data[, ...args])</code></a></li>
<li><a href="#console_console_dir_obj_options"><code>console.dir(obj[, options])</code></a></li>
<li><a href="#console_console_dirxml_data"><code>console.dirxml(...data)</code></a></li>
<li><a href="#console_console_error_data_args"><code>console.error([data][, ...args])</code></a></li>
<li><a href="#console_console_group_label"><code>console.group([...label])</code></a></li>
<li><a href="#console_console_groupcollapsed"><code>console.groupCollapsed()</code></a></li>
<li><a href="#console_console_groupend"><code>console.groupEnd()</code></a></li>
<li><a href="#console_console_info_data_args"><code>console.info([data][, ...args])</code></a></li>
<li><a href="#console_console_log_data_args"><code>console.log([data][, ...args])</code></a></li>
<li><a href="#console_console_table_tabulardata_properties"><code>console.table(tabularData[, properties])</code></a></li>
<li><a href="#console_console_time_label"><code>console.time([label])</code></a></li>
<li><a href="#console_console_timeend_label"><code>console.timeEnd([label])</code></a></li>
<li><a href="#console_console_timelog_label_data"><code>console.timeLog([label][, ...data])</code></a></li>
<li><a href="#console_console_trace_message_args"><code>console.trace([message][, ...args])</code></a></li>
<li><a href="#console_console_warn_data_args"><code>console.warn([data][, ...args])</code></a></li>
</ul>
</li>
<li>
<p><a href="#console_inspector_only_methods">Inspector only methods</a></p>
<ul>
<li><a href="#console_console_profile_label"><code>console.profile([label])</code></a></li>
<li><a href="#console_console_profileend_label"><code>console.profileEnd([label])</code></a></li>
<li><a href="#console_console_timestamp_label"><code>console.timeStamp([label])</code></a></li>
</ul>
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<h1>Console<span><a class="mark" href="#console_console" id="console_console">#</a></span></h1>
<p></p><div class="api_stability api_stability_2"><a href="documentation.html#documentation_stability_index">Stability: 2</a> - Stable</div><p></p>
<p>The <code>console</code> module provides a simple debugging console that is similar to the
JavaScript console mechanism provided by web browsers.</p>
<p>The module exports two specific components:</p>
<ul>
<li>A <code>Console</code> class with methods such as <code>console.log()</code>, <code>console.error()</code> and
<code>console.warn()</code> that can be used to write to any Node.js stream.</li>
<li>A global <code>console</code> instance configured to write to <a href="process.html#process_process_stdout"><code>process.stdout</code></a> and
<a href="process.html#process_process_stderr"><code>process.stderr</code></a>. The global <code>console</code> can be used without calling
<code>require('console')</code>.</li>
</ul>
<p><strong><em>Warning</em></strong>: The global console object's methods are neither consistently
synchronous like the browser APIs they resemble, nor are they consistently
asynchronous like all other Node.js streams. See the <a href="process.html#process_a_note_on_process_i_o">note on process I/O</a> for
more information.</p>
<p>Example using the global <code>console</code>:</p>
<pre><code class="language-js">console.log('hello world');
// Prints: hello world, to stdout
console.log('hello %s', 'world');
// Prints: hello world, to stdout
console.error(new Error('Whoops, something bad happened'));
// Prints: [Error: Whoops, something bad happened], to stderr
const name = 'Will Robinson';
console.warn(`Danger ${name}! Danger!`);
// Prints: Danger Will Robinson! Danger!, to stderr
</code></pre>
<p>Example using the <code>Console</code> class:</p>
<pre><code class="language-js">const out = getStreamSomehow();
const err = getStreamSomehow();
const myConsole = new console.Console(out, err);
myConsole.log('hello world');
// Prints: hello world, to out
myConsole.log('hello %s', 'world');
// Prints: hello world, to out
myConsole.error(new Error('Whoops, something bad happened'));
// Prints: [Error: Whoops, something bad happened], to err
const name = 'Will Robinson';
myConsole.warn(`Danger ${name}! Danger!`);
// Prints: Danger Will Robinson! Danger!, to err
</code></pre>
<h2>Class: <code>Console</code><span><a class="mark" href="#console_class_console" id="console_class_console">#</a></span></h2>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v8.0.0</td>
<td><p>Errors that occur while writing to the underlying streams will now be ignored by default.</p></td></tr>
</tbody></table>
</details>
</div>
<p>The <code>Console</code> class can be used to create a simple logger with configurable
output streams and can be accessed using either <code>require('console').Console</code>
or <code>console.Console</code> (or their destructured counterparts):</p>
<pre><code class="language-js">const { Console } = require('console');
</code></pre>
<pre><code class="language-js">const { Console } = console;
</code></pre>
<h3><code>new Console(stdout[, stderr][, ignoreErrors])</code><span><a class="mark" href="#console_new_console_stdout_stderr_ignoreerrors" id="console_new_console_stdout_stderr_ignoreerrors">#</a></span></h3>
<h3><code>new Console(options)</code><span><a class="mark" href="#console_new_console_options" id="console_new_console_options">#</a></span></h3>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v12.17.0</td>
<td><p>The <code>groupIndentation</code> option was introduced.</p></td></tr>
<tr><td>v11.7.0</td>
<td><p>The <code>inspectOptions</code> option is introduced.</p></td></tr>
<tr><td>v10.0.0</td>
<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>
<tr><td>v8.0.0</td>
<td><p>The <code>ignoreErrors</code> option was introduced.</p></td></tr>
</tbody></table>
</details>
</div>
<ul>
<li>
<p><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a></p>
<ul>
<li><code>stdout</code> <a href="stream.html#stream_class_stream_writable" class="type"><stream.Writable></a></li>
<li><code>stderr</code> <a href="stream.html#stream_class_stream_writable" class="type"><stream.Writable></a></li>
<li><code>ignoreErrors</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type"><boolean></a> Ignore errors when writing to the underlying
streams. <strong>Default:</strong> <code>true</code>.</li>
<li><code>colorMode</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type"><boolean></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> Set color support for this <code>Console</code> instance.
Setting to <code>true</code> enables coloring while inspecting values. Setting to
<code>false</code> disables coloring while inspecting values. Setting to
<code>'auto'</code> makes color support depend on the value of the <code>isTTY</code> property
and the value returned by <code>getColorDepth()</code> on the respective stream. This
option can not be used, if <code>inspectOptions.colors</code> is set as well.
<strong>Default:</strong> <code>'auto'</code>.</li>
<li><code>inspectOptions</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a> Specifies options that are passed along to
<a href="util.html#util_util_inspect_object_options"><code>util.inspect()</code></a>.</li>
<li><code>groupIndentation</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><number></a> Set group indentation.
<strong>Default:</strong> <code>2</code>.</li>
</ul>
</li>
</ul>
<p>Creates a new <code>Console</code> with one or two writable stream instances. <code>stdout</code> is a
writable stream to print log or info output. <code>stderr</code> is used for warning or
error output. If <code>stderr</code> is not provided, <code>stdout</code> is used for <code>stderr</code>.</p>
<pre><code class="language-js">const output = fs.createWriteStream('./stdout.log');
const errorOutput = fs.createWriteStream('./stderr.log');
// Custom simple logger
const logger = new Console({ stdout: output, stderr: errorOutput });
// use it like console
const count = 5;
logger.log('count: %d', count);
// In stdout.log: count 5
</code></pre>
<p>The global <code>console</code> is a special <code>Console</code> whose output is sent to
<a href="process.html#process_process_stdout"><code>process.stdout</code></a> and <a href="process.html#process_process_stderr"><code>process.stderr</code></a>. It is equivalent to calling:</p>
<pre><code class="language-js">new Console({ stdout: process.stdout, stderr: process.stderr });
</code></pre>
<h3><code>console.assert(value[, ...message])</code><span><a class="mark" href="#console_console_assert_value_message" id="console_console_assert_value_message">#</a></span></h3>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v10.0.0</td>
<td><p>The implementation is now spec compliant and does not throw anymore.</p></td></tr>
<tr><td>v0.1.101</td>
<td><p><span>Added in: v0.1.101</span></p></td></tr>
</tbody></table>
</details>
</div>
<ul>
<li><code>value</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type"><any></a> The value tested for being truthy.</li>
<li><code>...message</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type"><any></a> All arguments besides <code>value</code> are used as error message.</li>
</ul>
<p>A simple assertion test that verifies whether <code>value</code> is truthy. If it is not,
<code>Assertion failed</code> is logged. If provided, the error <code>message</code> is formatted
using <a href="util.html#util_util_format_format_args"><code>util.format()</code></a> by passing along all message arguments. The output is
used as the error message.</p>
<pre><code class="language-js">console.assert(true, 'does nothing');
// OK
console.assert(false, 'Whoops %s work', 'didn\'t');
// Assertion failed: Whoops didn't work
</code></pre>
<p>Calling <code>console.assert()</code> with a falsy assertion will only cause the <code>message</code>
to be printed to the console without interrupting execution of subsequent code.</p>
<h3><code>console.clear()</code><span><a class="mark" href="#console_console_clear" id="console_console_clear">#</a></span></h3>
<div class="api_metadata">
<span>Added in: v8.3.0</span>
</div>
<p>When <code>stdout</code> is a TTY, calling <code>console.clear()</code> will attempt to clear the
TTY. When <code>stdout</code> is not a TTY, this method does nothing.</p>
<p>The specific operation of <code>console.clear()</code> can vary across operating systems
and terminal types. For most Linux operating systems, <code>console.clear()</code>
operates similarly to the <code>clear</code> shell command. On Windows, <code>console.clear()</code>
will clear only the output in the current terminal viewport for the Node.js
binary.</p>
<h3><code>console.count([label])</code><span><a class="mark" href="#console_console_count_label" id="console_console_count_label">#</a></span></h3>
<div class="api_metadata">
<span>Added in: v8.3.0</span>
</div>
<ul>
<li><code>label</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> The display label for the counter. <strong>Default:</strong> <code>'default'</code>.</li>
</ul>
<p>Maintains an internal counter specific to <code>label</code> and outputs to <code>stdout</code> the
number of times <code>console.count()</code> has been called with the given <code>label</code>.</p>
<!-- eslint-skip -->
<pre><code class="language-js">> console.count()
default: 1
undefined
> console.count('default')
default: 2
undefined
> console.count('abc')
abc: 1
undefined
> console.count('xyz')
xyz: 1
undefined
> console.count('abc')
abc: 2
undefined
> console.count()
default: 3
undefined
>
</code></pre>
<h3><code>console.countReset([label])</code><span><a class="mark" href="#console_console_countreset_label" id="console_console_countreset_label">#</a></span></h3>
<div class="api_metadata">
<span>Added in: v8.3.0</span>
</div>
<ul>
<li><code>label</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> The display label for the counter. <strong>Default:</strong> <code>'default'</code>.</li>
</ul>
<p>Resets the internal counter specific to <code>label</code>.</p>
<!-- eslint-skip -->
<pre><code class="language-js">> console.count('abc');
abc: 1
undefined
> console.countReset('abc');
undefined
> console.count('abc');
abc: 1
undefined
>
</code></pre>
<h3><code>console.debug(data[, ...args])</code><span><a class="mark" href="#console_console_debug_data_args" id="console_console_debug_data_args">#</a></span></h3>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v8.10.0</td>
<td><p><code>console.debug</code> is now an alias for <code>console.log</code>.</p></td></tr>
<tr><td>v8.0.0</td>
<td><p><span>Added in: v8.0.0</span></p></td></tr>
</tbody></table>
</details>
</div>
<ul>
<li><code>data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type"><any></a></li>
<li><code>...args</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type"><any></a></li>
</ul>
<p>The <code>console.debug()</code> function is an alias for <a href="#console_console_log_data_args"><code>console.log()</code></a>.</p>
<h3><code>console.dir(obj[, options])</code><span><a class="mark" href="#console_console_dir_obj_options" id="console_console_dir_obj_options">#</a></span></h3>
<div class="api_metadata">
<span>Added in: v0.1.101</span>
</div>
<ul>
<li><code>obj</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type"><any></a></li>
<li>
<p><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a></p>
<ul>
<li><code>showHidden</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type"><boolean></a> If <code>true</code> then the object's non-enumerable and symbol
properties will be shown too. <strong>Default:</strong> <code>false</code>.</li>
<li><code>depth</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><number></a> Tells <a href="util.html#util_util_inspect_object_options"><code>util.inspect()</code></a> how many times to recurse while
formatting the object. This is useful for inspecting large complicated
objects. To make it recurse indefinitely, pass <code>null</code>. <strong>Default:</strong> <code>2</code>.</li>
<li><code>colors</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type"><boolean></a> If <code>true</code>, then the output will be styled with ANSI color
codes. Colors are customizable;
see <a href="util.html#util_customizing_util_inspect_colors">customizing <code>util.inspect()</code> colors</a>. <strong>Default:</strong> <code>false</code>.</li>
</ul>
</li>
</ul>
<p>Uses <a href="util.html#util_util_inspect_object_options"><code>util.inspect()</code></a> on <code>obj</code> and prints the resulting string to <code>stdout</code>.
This function bypasses any custom <code>inspect()</code> function defined on <code>obj</code>.</p>
<h3><code>console.dirxml(...data)</code><span><a class="mark" href="#console_console_dirxml_data" id="console_console_dirxml_data">#</a></span></h3>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v9.3.0</td>
<td><p><code>console.dirxml</code> now calls <code>console.log</code> for its arguments.</p></td></tr>
<tr><td>v8.0.0</td>
<td><p><span>Added in: v8.0.0</span></p></td></tr>
</tbody></table>
</details>
</div>
<ul>
<li><code>...data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type"><any></a></li>
</ul>
<p>This method calls <code>console.log()</code> passing it the arguments received.
This method does not produce any XML formatting.</p>
<h3><code>console.error([data][, ...args])</code><span><a class="mark" href="#console_console_error_data_args" id="console_console_error_data_args">#</a></span></h3>
<div class="api_metadata">
<span>Added in: v0.1.100</span>
</div>
<ul>
<li><code>data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type"><any></a></li>
<li><code>...args</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type"><any></a></li>
</ul>
<p>Prints to <code>stderr</code> with newline. Multiple arguments can be passed, with the
first used as the primary message and all additional used as substitution
values 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
<a href="util.html#util_util_format_format_args"><code>util.format()</code></a>).</p>
<pre><code class="language-js">const code = 5;
console.error('error #%d', code);
// Prints: error #5, to stderr
console.error('error', code);
// Prints: error 5, to stderr
</code></pre>
<p>If formatting elements (e.g. <code>%d</code>) are not found in the first string then
<a href="util.html#util_util_inspect_object_options"><code>util.inspect()</code></a> is called on each argument and the resulting string
values are concatenated. See <a href="util.html#util_util_format_format_args"><code>util.format()</code></a> for more information.</p>
<h3><code>console.group([...label])</code><span><a class="mark" href="#console_console_group_label" id="console_console_group_label">#</a></span></h3>
<div class="api_metadata">
<span>Added in: v8.5.0</span>
</div>
<ul>
<li><code>...label</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type"><any></a></li>
</ul>
<p>Increases indentation of subsequent lines by spaces for <code>groupIndentation</code>
length.</p>
<p>If one or more <code>label</code>s are provided, those are printed first without the
additional indentation.</p>
<h3><code>console.groupCollapsed()</code><span><a class="mark" href="#console_console_groupcollapsed" id="console_console_groupcollapsed">#</a></span></h3>
<div class="api_metadata">
<span>Added in: v8.5.0</span>
</div>
<p>An alias for <a href="#console_console_group_label"><code>console.group()</code></a>.</p>
<h3><code>console.groupEnd()</code><span><a class="mark" href="#console_console_groupend" id="console_console_groupend">#</a></span></h3>
<div class="api_metadata">
<span>Added in: v8.5.0</span>
</div>
<p>Decreases indentation of subsequent lines by spaces for <code>groupIndentation</code>
length.</p>
<h3><code>console.info([data][, ...args])</code><span><a class="mark" href="#console_console_info_data_args" id="console_console_info_data_args">#</a></span></h3>
<div class="api_metadata">
<span>Added in: v0.1.100</span>
</div>
<ul>
<li><code>data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type"><any></a></li>
<li><code>...args</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type"><any></a></li>
</ul>
<p>The <code>console.info()</code> function is an alias for <a href="#console_console_log_data_args"><code>console.log()</code></a>.</p>
<h3><code>console.log([data][, ...args])</code><span><a class="mark" href="#console_console_log_data_args" id="console_console_log_data_args">#</a></span></h3>
<div class="api_metadata">
<span>Added in: v0.1.100</span>
</div>
<ul>
<li><code>data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type"><any></a></li>
<li><code>...args</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type"><any></a></li>
</ul>
<p>Prints to <code>stdout</code> with newline. Multiple arguments can be passed, with the
first used as the primary message and all additional used as substitution
values 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
<a href="util.html#util_util_format_format_args"><code>util.format()</code></a>).</p>
<pre><code class="language-js">const count = 5;
console.log('count: %d', count);
// Prints: count: 5, to stdout
console.log('count:', count);
// Prints: count: 5, to stdout
</code></pre>
<p>See <a href="util.html#util_util_format_format_args"><code>util.format()</code></a> for more information.</p>
<h3><code>console.table(tabularData[, properties])</code><span><a class="mark" href="#console_console_table_tabulardata_properties" id="console_console_table_tabulardata_properties">#</a></span></h3>
<div class="api_metadata">
<span>Added in: v10.0.0</span>
</div>
<ul>
<li><code>tabularData</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type"><any></a></li>
<li><code>properties</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string[]></a> Alternate properties for constructing the table.</li>
</ul>
<p>Try to construct a table with the columns of the properties of <code>tabularData</code>
(or use <code>properties</code>) and rows of <code>tabularData</code> and log it. Falls back to just
logging the argument if it can’t be parsed as tabular.</p>
<pre><code class="language-js">// These can't be parsed as tabular data
console.table(Symbol());
// Symbol()
console.table(undefined);
// undefined
console.table([{ a: 1, b: 'Y' }, { a: 'Z', b: 2 }]);
// ┌─────────┬─────┬─────┐
// │ (index) │ a │ b │
// ├─────────┼─────┼─────┤
// │ 0 │ 1 │ 'Y' │
// │ 1 │ 'Z' │ 2 │
// └─────────┴─────┴─────┘
console.table([{ a: 1, b: 'Y' }, { a: 'Z', b: 2 }], ['a']);
// ┌─────────┬─────┐
// │ (index) │ a │
// ├─────────┼─────┤
// │ 0 │ 1 │
// │ 1 │ 'Z' │
// └─────────┴─────┘
</code></pre>
<h3><code>console.time([label])</code><span><a class="mark" href="#console_console_time_label" id="console_console_time_label">#</a></span></h3>
<div class="api_metadata">
<span>Added in: v0.1.104</span>
</div>
<ul>
<li><code>label</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> <strong>Default:</strong> <code>'default'</code></li>
</ul>
<p>Starts a timer that can be used to compute the duration of an operation. Timers
are identified by a unique <code>label</code>. Use the same <code>label</code> when calling
<a href="#console_console_timeend_label"><code>console.timeEnd()</code></a> to stop the timer and output the elapsed time in
milliseconds to <code>stdout</code>. Timer durations are accurate to the sub-millisecond.</p>
<h3><code>console.timeEnd([label])</code><span><a class="mark" href="#console_console_timeend_label" id="console_console_timeend_label">#</a></span></h3>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v6.0.0</td>
<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>
<tr><td>v0.1.104</td>
<td><p><span>Added in: v0.1.104</span></p></td></tr>
</tbody></table>
</details>
</div>
<ul>
<li><code>label</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> <strong>Default:</strong> <code>'default'</code></li>
</ul>
<p>Stops a timer that was previously started by calling <a href="#console_console_time_label"><code>console.time()</code></a> and
prints the result to <code>stdout</code>:</p>
<pre><code class="language-js">console.time('100-elements');
for (let i = 0; i < 100; i++) {}
console.timeEnd('100-elements');
// prints 100-elements: 225.438ms
</code></pre>
<h3><code>console.timeLog([label][, ...data])</code><span><a class="mark" href="#console_console_timelog_label_data" id="console_console_timelog_label_data">#</a></span></h3>
<div class="api_metadata">
<span>Added in: v10.7.0</span>
</div>
<ul>
<li><code>label</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> <strong>Default:</strong> <code>'default'</code></li>
<li><code>...data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type"><any></a></li>
</ul>
<p>For a timer that was previously started by calling <a href="#console_console_time_label"><code>console.time()</code></a>, prints
the elapsed time and other <code>data</code> arguments to <code>stdout</code>:</p>
<pre><code class="language-js">console.time('process');
const value = expensiveProcess1(); // Returns 42
console.timeLog('process', value);
// Prints "process: 365.227ms 42".
doExpensiveProcess2(value);
console.timeEnd('process');
</code></pre>
<h3><code>console.trace([message][, ...args])</code><span><a class="mark" href="#console_console_trace_message_args" id="console_console_trace_message_args">#</a></span></h3>
<div class="api_metadata">
<span>Added in: v0.1.104</span>
</div>
<ul>
<li><code>message</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type"><any></a></li>
<li><code>...args</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type"><any></a></li>
</ul>
<p>Prints to <code>stderr</code> the string <code>'Trace: '</code>, followed by the <a href="util.html#util_util_format_format_args"><code>util.format()</code></a>
formatted message and stack trace to the current position in the code.</p>
<pre><code class="language-js">console.trace('Show me');
// Prints: (stack trace will vary based on where trace is called)
// Trace: Show me
// at repl:2:9
// at REPLServer.defaultEval (repl.js:248:27)
// at bound (domain.js:287:14)
// at REPLServer.runBound [as eval] (domain.js:300:12)
// at REPLServer.<anonymous> (repl.js:412:12)
// at emitOne (events.js:82:20)
// at REPLServer.emit (events.js:169:7)
// at REPLServer.Interface._onLine (readline.js:210:10)
// at REPLServer.Interface._line (readline.js:549:8)
// at REPLServer.Interface._ttyWrite (readline.js:826:14)
</code></pre>
<h3><code>console.warn([data][, ...args])</code><span><a class="mark" href="#console_console_warn_data_args" id="console_console_warn_data_args">#</a></span></h3>
<div class="api_metadata">
<span>Added in: v0.1.100</span>
</div>
<ul>
<li><code>data</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type"><any></a></li>
<li><code>...args</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types" class="type"><any></a></li>
</ul>
<p>The <code>console.warn()</code> function is an alias for <a href="#console_console_error_data_args"><code>console.error()</code></a>.</p>
<h2>Inspector only methods<span><a class="mark" href="#console_inspector_only_methods" id="console_inspector_only_methods">#</a></span></h2>
<p>The following methods are exposed by the V8 engine in the general API but do
not display anything unless used in conjunction with the <a href="debugger.html">inspector</a>
(<code>--inspect</code> flag).</p>
<h3><code>console.profile([label])</code><span><a class="mark" href="#console_console_profile_label" id="console_console_profile_label">#</a></span></h3>
<div class="api_metadata">
<span>Added in: v8.0.0</span>
</div>
<ul>
<li><code>label</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li>
</ul>
<p>This method does not display anything unless used in the inspector. The
<code>console.profile()</code> method starts a JavaScript CPU profile with an optional
label until <a href="#console_console_profileend_label"><code>console.profileEnd()</code></a> is called. The profile is then added to
the <strong>Profile</strong> panel of the inspector.</p>
<pre><code class="language-js">console.profile('MyLabel');
// Some code
console.profileEnd('MyLabel');
// Adds the profile 'MyLabel' to the Profiles panel of the inspector.
</code></pre>
<h3><code>console.profileEnd([label])</code><span><a class="mark" href="#console_console_profileend_label" id="console_console_profileend_label">#</a></span></h3>
<div class="api_metadata">
<span>Added in: v8.0.0</span>
</div>
<ul>
<li><code>label</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li>
</ul>
<p>This method does not display anything unless used in the inspector. Stops the
current JavaScript CPU profiling session if one has been started and prints
the report to the <strong>Profiles</strong> panel of the inspector. See
<a href="#console_console_profile_label"><code>console.profile()</code></a> for an example.</p>
<p>If this method is called without a label, the most recently started profile is
stopped.</p>
<h3><code>console.timeStamp([label])</code><span><a class="mark" href="#console_console_timestamp_label" id="console_console_timestamp_label">#</a></span></h3>
<div class="api_metadata">
<span>Added in: v8.0.0</span>
</div>
<ul>
<li><code>label</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li>
</ul>
<p>This method does not display anything unless used in the inspector. The
<code>console.timeStamp()</code> method adds an event with the label <code>'label'</code> to the
<strong>Timeline</strong> panel of the inspector.</p>
</div>
</div>
</div>
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