| <!doctype html> |
| <html lang="en"> |
| <head> |
| <meta charset="utf-8"> |
| <title>console Node.js v0.10.24 Manual & Documentation</title> |
| <link rel="stylesheet" href="assets/style.css"> |
| <link rel="stylesheet" href="assets/sh.css"> |
| <link rel="canonical" href="http://nodejs.org/api/console.html"> |
| </head> |
| <body class="alt apidoc" id="api-section-console"> |
| <div id="intro" class="interior"> |
| <a href="/" title="Go back to the home page"> |
| <img id="logo" src="http://nodejs.org/images/logo-light.png" alt="node.js"> |
| </a> |
| </div> |
| <div id="content" class="clearfix"> |
| <div id="column2" class="interior"> |
| <ul> |
| <li><a href="/" class="home">Home</a></li> |
| <li><a href="/download/" class="download">Download</a></li> |
| <li><a href="/about/" class="about">About</a></li> |
| <li><a href="http://npmjs.org/" class="npm">npm Registry</a></li> |
| <li><a href="http://nodejs.org/api/" class="docs current">Docs</a></li> |
| <li><a href="http://blog.nodejs.org" class="blog">Blog</a></li> |
| <li><a href="/community/" class="community">Community</a></li> |
| <li><a href="/logos/" class="logos">Logos</a></li> |
| <li><a href="http://jobs.nodejs.org/" class="jobs">Jobs</a></li> |
| </ul> |
| <p class="twitter"><a href="http://twitter.com/nodejs">@nodejs</a></p> |
| </div> |
| |
| <div id="column1" class="interior"> |
| <header> |
| <h1>Node.js v0.10.24 Manual & Documentation</h1> |
| <div id="gtoc"> |
| <p> |
| <a href="index.html" name="toc">Index</a> | |
| <a href="all.html">View on single page</a> | |
| <a href="console.json">View as JSON</a> |
| </p> |
| </div> |
| <hr> |
| </header> |
| |
| <div id="toc"> |
| <h2>Table of Contents</h2> |
| <ul> |
| <li><a href="#console_console">console</a><ul> |
| <li><a href="#console_console_log_data">console.log([data], [...])</a></li> |
| <li><a href="#console_console_info_data">console.info([data], [...])</a></li> |
| <li><a href="#console_console_error_data">console.error([data], [...])</a></li> |
| <li><a href="#console_console_warn_data">console.warn([data], [...])</a></li> |
| <li><a href="#console_console_dir_obj">console.dir(obj)</a></li> |
| <li><a href="#console_console_time_label">console.time(label)</a></li> |
| <li><a href="#console_console_timeend_label">console.timeEnd(label)</a></li> |
| <li><a href="#console_console_trace_label">console.trace(label)</a></li> |
| <li><a href="#console_console_assert_expression_message">console.assert(expression, [message])</a></li> |
| </ul> |
| </li> |
| </ul> |
| |
| </div> |
| |
| <div id="apicontent"> |
| <h1>console<span><a class="mark" href="#console_console" id="console_console">#</a></span></h1> |
| <pre class="api_stability_4">Stability: 4 - API Frozen</pre><div class="signature"><ul> |
| <li><span class="type">Object</span></li> |
| </div></ul> |
| <!--type=global--> |
| |
| <p>For printing to stdout and stderr. Similar to the console object functions |
| provided by most web browsers, here the output is sent to stdout or stderr. |
| |
| </p> |
| <p>The console functions are synchronous when the destination is a terminal or |
| a file (to avoid lost messages in case of premature exit) and asynchronous |
| when it's a pipe (to avoid blocking for long periods of time). |
| |
| </p> |
| <p>That is, in the following example, stdout is non-blocking while stderr |
| is blocking: |
| |
| </p> |
| <pre><code>$ node script.js 2> error.log | tee info.log</code></pre> |
| <p>In daily use, the blocking/non-blocking dichotomy is not something you |
| should worry about unless you log huge amounts of data. |
| |
| |
| </p> |
| <h2>console.log([data], [...])<span><a class="mark" href="#console_console_log_data" id="console_console_log_data">#</a></span></h2> |
| <p>Prints to stdout with newline. This function can take multiple arguments in a |
| <code>printf()</code>-like way. Example: |
| |
| </p> |
| <pre><code>console.log('count: %d', count);</code></pre> |
| <p>If formatting elements are not found in the first string then <code>util.inspect</code> |
| is used on each argument. See <a href="util.html#util_util_format_format">util.format()</a> for more information. |
| |
| </p> |
| <h2>console.info([data], [...])<span><a class="mark" href="#console_console_info_data" id="console_console_info_data">#</a></span></h2> |
| <p>Same as <code>console.log</code>. |
| |
| </p> |
| <h2>console.error([data], [...])<span><a class="mark" href="#console_console_error_data" id="console_console_error_data">#</a></span></h2> |
| <p>Same as <code>console.log</code> but prints to stderr. |
| |
| </p> |
| <h2>console.warn([data], [...])<span><a class="mark" href="#console_console_warn_data" id="console_console_warn_data">#</a></span></h2> |
| <p>Same as <code>console.error</code>. |
| |
| </p> |
| <h2>console.dir(obj)<span><a class="mark" href="#console_console_dir_obj" id="console_console_dir_obj">#</a></span></h2> |
| <p>Uses <code>util.inspect</code> on <code>obj</code> and prints resulting string to stdout. |
| |
| </p> |
| <h2>console.time(label)<span><a class="mark" href="#console_console_time_label" id="console_console_time_label">#</a></span></h2> |
| <p>Mark a time. |
| |
| </p> |
| <h2>console.timeEnd(label)<span><a class="mark" href="#console_console_timeend_label" id="console_console_timeend_label">#</a></span></h2> |
| <p>Finish timer, record output. Example: |
| |
| </p> |
| <pre><code>console.time('100-elements'); |
| for (var i = 0; i < 100; i++) { |
| ; |
| } |
| console.timeEnd('100-elements');</code></pre> |
| <h2>console.trace(label)<span><a class="mark" href="#console_console_trace_label" id="console_console_trace_label">#</a></span></h2> |
| <p>Print a stack trace to stderr of the current position. |
| |
| </p> |
| <h2>console.assert(expression, [message])<span><a class="mark" href="#console_console_assert_expression_message" id="console_console_assert_expression_message">#</a></span></h2> |
| <p>Same as <a href="assert.html#assert_assert_value_message_assert_ok_value_message">assert.ok()</a> where if the <code>expression</code> evaluates as <code>false</code> throw an |
| AssertionError with <code>message</code>. |
| |
| </p> |
| |
| </div> |
| </div> |
| </div> |
| <div id="footer"> |
| <a href="http://joyent.com" class="joyent-logo">Joyent</a> |
| <ul class="clearfix"> |
| <li><a href="/">Node.js</a></li> |
| <li><a href="/download/">Download</a></li> |
| <li><a href="/about/">About</a></li> |
| <li><a href="http://npmjs.org/">npm Registry</a></li> |
| <li><a href="http://nodejs.org/api/">Docs</a></li> |
| <li><a href="http://blog.nodejs.org">Blog</a></li> |
| <li><a href="/community/">Community</a></li> |
| <li><a href="/logos/">Logos</a></li> |
| <li><a href="http://jobs.nodejs.org/">Jobs</a></li> |
| <li><a href="http://twitter.com/nodejs" class="twitter">@nodejs</a></li> |
| </ul> |
| |
| <p>Copyright <a href="http://joyent.com/">Joyent, Inc</a>, Node.js is a <a href="/trademark-policy.pdf">trademark</a> of Joyent, Inc. View <a href="https://raw.github.com/joyent/node/v0.10.24/LICENSE">license</a>.</p> |
| </div> |
| |
| <script src="../sh_main.js"></script> |
| <script src="../sh_javascript.min.js"></script> |
| <script>highlight(undefined, undefined, 'pre');</script> |
| <script> |
| window._gaq = [['_setAccount', 'UA-10874194-2'], ['_trackPageview']]; |
| (function(d, t) { |
| var g = d.createElement(t), |
| s = d.getElementsByTagName(t)[0]; |
| g.src = '//www.google-analytics.com/ga.js'; |
| s.parentNode.insertBefore(g, s); |
| }(document, 'script')); |
| </script> |
| </body> |
| </html> |
| |