workshopper-browser-guide

<!doctype html> <html lang="en"> <head> <meta charset="utf-8"> <title>console Node.js v0.10.35 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"> <script type="text/javascript" src="//use.typekit.net/mse5tqx.js"></script> <script type="text/javascript">try{Typekit.load();}catch(e){}</script> </head> <body class="alt apidoc int docs" id="docs"> <div id="nav"> <img id="logo" src="assets/logo.svg" alt="node.js"> <ul> <li><a href="http://nodejs.org">Home</a></li> <li><a href="http://nodejs.org/download/">Downloads</a></li> <li class="active"><a href="http://nodejs.org/documentation/">Docs</a></li> <li><a href="http://nodejs.org/community/">Community</a></li> <li><a href="http://nodejs.org/about/">About</a></li> <li><a href="http://jobs.nodejs.org">Jobs</a></li> <li><a href="http://blog.nodejs.org">Blog</a></li> </ul> </div> <div id="content-wrap"> <div id="content" class="clearfix"> <div id="column2" class="interior">  <ul class="docs-nav"> <li><a href="http://nodejs.org/documentation/">About Docs</a></li> <li><a href="http://nodejs.org/documentation/tutorials/">Tutorials</a></li> <li><a href="http://nodejs.org/documentation/contributing/">Contributing</a></li> <li><a href="http://nodejs.org/documentation/localization/">Localization</a></li> <li class="active"><a href="http://nodejs.org/api/">API Docs</a></li> </ul> </div> <div id="column1" class="interior"> <header> <h1>Node.js v0.10.35 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_message">console.trace(message, [...])</a></li> <li><a href="#console_console_assert_value_message">console.assert(value, [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>  <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(message, [...])<span><a class="mark" href="#console_console_trace_message" id="console_console_trace_message">#</a></span></h2> <p>Print to stderr <code>'Trace :'</code>, followed by the formatted message and stack trace to the current position. </p> <h2>console.assert(value, [message], [...])<span><a class="mark" href="#console_console_assert_value_message" id="console_console_assert_value_message">#</a></span></h2> <p>Similar to <a href="assert.html#assert_assert_value_message_assert_ok_value_message">assert.ok()</a>, but the error message is formatted as <code>util.format(message...)</code>. </p> </div> </div> </div> </div> <div id="footer"> <div class="foot-1"> <a href="http://www.joyent.com"><h5>The Node.js Project is Sponsored by</h5> <img src="assets/joyent-footer.svg" width="200"> <p class="tag">Production Node +<br>High Performance Infrastructure</p></a> <a href="https://my.joyent.com/landing/signup/701800000015696" class="button getstarted">Get Started</a> </div> <div class="foot-2"> <div class="foot-nav"> <ul> <li><a href="http://nodejs.org/download/">Downloads</a></li> </ul> <ul> <li><a href="http://nodejs.org/documentation/">Documentation</a></li> <li><a href="http://nodejs.org/api/">API Docs</a></li> <li><a href="http://nodejs.org/documentation/tutorials/">Tutorials</a></li> <li><a href="http://nodejs.org/documentation/localization/">Localization</a></li> </ul> <ul> <li><a href="http://nodejs.org/community/">Community</a></li> <li><a href="https://github.com/joyent/node/issues">Github Issues</a></li> <li><a href="http://groups.google.com/group/nodejs">Mailing List</a></li> <li><a href="http://webchat.freenode.net/?channels=node.js">IRC</a></li> <li><a href="https://twitter.com/nodejs">Twitter</a></li> </ul> <ul> <li><a href="http://nodejs.org/about/">About</a></li> <li><a href="http://nodejs.org/about/organization/">Organization</a></li> <li><a href="http://nodejs.org/about/core-team/">Core Team</a></li> <li><a href="http://nodejs.org/about/resources/">Resources</a></li> </ul> <ul> <li><a href="http://blog.nodejs.org">Blog</a></li> </ul> </div> <p class="copyright">Copyright 2014 <a href="http://joyent.com/">Joyent, Inc</a>, Node.js is a <a href="https://nodejs.org/images/trademark-policy.pdf">trademark</a> of Joyent, Inc. <a href="https://raw.github.com/joyent/node/v0.10.35/LICENSE">View license</a>.</p> </div> </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>