%PDF- %PDF-
Direktori : /usr/share/doc/nodejs/api/ |
Current File : //usr/share/doc/nodejs/api/globals.html |
<!doctype html> <html lang="en"> <head> <meta charset="utf-8"> <meta name="viewport" content="width=device-width"> <meta name="nodejs.org:node-version" content="v12.22.9"> <title>Global objects | Node.js v12.22.9 Documentation</title> <link rel="stylesheet" href="assets/style.css"> <link rel="stylesheet" href="assets/hljs.css"> <link rel="canonical" href="globals.html"> </head> <body class="alt apidoc" id="api-section-globals"> <div id="content" class="clearfix"> <div id="column2" class="interior"> <div id="intro" class="interior"> <a href="/" title="Go back to the home page"> Node.js </a> </div> <ul> <li><a class="nav-documentation" href="documentation.html">About this documentation</a></li> <li><a class="nav-synopsis" href="synopsis.html">Usage and example</a></li> </ul> <hr class="line"/> <ul> <li><a class="nav-assert" href="assert.html">Assertion testing</a></li> <li><a class="nav-async_hooks" href="async_hooks.html">Async hooks</a></li> <li><a class="nav-buffer" href="buffer.html">Buffer</a></li> <li><a class="nav-addons" href="addons.html">C++ Addons</a></li> <li><a class="nav-n-api" href="n-api.html">C/C++ Addons with N-API</a></li> <li><a class="nav-embedding" href="embedding.html">C++ Embedder API</a></li> <li><a class="nav-child_process" href="child_process.html">Child Processes</a></li> <li><a class="nav-cluster" href="cluster.html">Cluster</a></li> <li><a class="nav-cli" href="cli.html">Command line options</a></li> <li><a class="nav-console" href="console.html">Console</a></li> <li><a class="nav-crypto" href="crypto.html">Crypto</a></li> <li><a class="nav-debugger" href="debugger.html">Debugger</a></li> <li><a class="nav-deprecations" href="deprecations.html">Deprecated APIs</a></li> <li><a class="nav-dns" href="dns.html">DNS</a></li> <li><a class="nav-domain" href="domain.html">Domain</a></li> <li><a class="nav-errors" href="errors.html">Errors</a></li> <li><a class="nav-events" href="events.html">Events</a></li> <li><a class="nav-fs" href="fs.html">File system</a></li> <li><a class="nav-globals active" href="globals.html">Globals</a></li> <li><a class="nav-http" href="http.html">HTTP</a></li> <li><a class="nav-http2" href="http2.html">HTTP/2</a></li> <li><a class="nav-https" href="https.html">HTTPS</a></li> <li><a class="nav-inspector" href="inspector.html">Inspector</a></li> <li><a class="nav-intl" href="intl.html">Internationalization</a></li> <li><a class="nav-modules" href="modules.html">Modules: CommonJS modules</a></li> <li><a class="nav-esm" href="esm.html">Modules: ECMAScript modules</a></li> <li><a class="nav-module" href="module.html">Modules: <code>module</code> API</a></li> <li><a class="nav-packages" href="packages.html">Modules: Packages</a></li> <li><a class="nav-net" href="net.html">Net</a></li> <li><a class="nav-os" href="os.html">OS</a></li> <li><a class="nav-path" href="path.html">Path</a></li> <li><a class="nav-perf_hooks" href="perf_hooks.html">Performance hooks</a></li> <li><a class="nav-policy" href="policy.html">Policies</a></li> <li><a class="nav-process" href="process.html">Process</a></li> <li><a class="nav-punycode" href="punycode.html">Punycode</a></li> <li><a class="nav-querystring" href="querystring.html">Query strings</a></li> <li><a class="nav-readline" href="readline.html">Readline</a></li> <li><a class="nav-repl" href="repl.html">REPL</a></li> <li><a class="nav-report" href="report.html">Report</a></li> <li><a class="nav-stream" href="stream.html">Stream</a></li> <li><a class="nav-string_decoder" href="string_decoder.html">String decoder</a></li> <li><a class="nav-timers" href="timers.html">Timers</a></li> <li><a class="nav-tls" href="tls.html">TLS/SSL</a></li> <li><a class="nav-tracing" href="tracing.html">Trace events</a></li> <li><a class="nav-tty" href="tty.html">TTY</a></li> <li><a class="nav-dgram" href="dgram.html">UDP/datagram</a></li> <li><a class="nav-url" href="url.html">URL</a></li> <li><a class="nav-util" href="util.html">Utilities</a></li> <li><a class="nav-v8" href="v8.html">V8</a></li> <li><a class="nav-vm" href="vm.html">VM</a></li> <li><a class="nav-wasi" href="wasi.html">WASI</a></li> <li><a class="nav-worker_threads" href="worker_threads.html">Worker threads</a></li> <li><a class="nav-zlib" href="zlib.html">Zlib</a></li> </ul> <hr class="line"/> <ul> <li><a class="nav-https-github-com-nodejs-node" href="https://github.com/nodejs/node">Code repository and issue tracker</a></li> </ul> </div> <div id="column1" data-id="globals" class="interior"> <header> <h1>Node.js v12.22.9 Documentation</h1> <div id="gtoc"> <ul> <li> <a href="index.html">Index</a> </li> <li> <a href="all.html">View on single page</a> </li> <li> <a href="globals.json">View as JSON</a> </li> <li class="edit_on_github"><a href="https://github.com/nodejs/node/edit/master/doc/api/globals.md"><span class="github_icon"><svg height="16" width="16" viewBox="0 0 16.1 16.1" fill="currentColor"><path d="M8 0a8 8 0 0 0-2.5 15.6c.4 0 .5-.2.5-.4v-1.5c-2 .4-2.5-.5-2.7-1 0-.1-.5-.9-.8-1-.3-.2-.7-.6 0-.6.6 0 1 .6 1.2.8.7 1.2 1.9 1 2.4.7 0-.5.2-.9.5-1-1.8-.3-3.7-1-3.7-4 0-.9.3-1.6.8-2.2 0-.2-.3-1 .1-2 0 0 .7-.3 2.2.7a7.4 7.4 0 0 1 4 0c1.5-1 2.2-.8 2.2-.8.5 1.1.2 2 .1 2.1.5.6.8 1.3.8 2.2 0 3-1.9 3.7-3.6 4 .3.2.5.7.5 1.4v2.2c0 .2.1.5.5.4A8 8 0 0 0 16 8a8 8 0 0 0-8-8z"/></svg></span>Edit on GitHub</a></li> </ul> </div> <hr> </header> <div id="toc"> <h2>Table of Contents</h2> <ul> <li><a href="#globals_global_objects">Global objects</a><ul> <li><a href="#globals_class_buffer">Class: <code>Buffer</code></a></li> <li><a href="#globals_dirname"><code>__dirname</code></a></li> <li><a href="#globals_filename"><code>__filename</code></a></li> <li><a href="#globals_clearimmediate_immediateobject"><code>clearImmediate(immediateObject)</code></a></li> <li><a href="#globals_clearinterval_intervalobject"><code>clearInterval(intervalObject)</code></a></li> <li><a href="#globals_cleartimeout_timeoutobject"><code>clearTimeout(timeoutObject)</code></a></li> <li><a href="#globals_console"><code>console</code></a></li> <li><a href="#globals_exports"><code>exports</code></a></li> <li><a href="#globals_global"><code>global</code></a></li> <li><a href="#globals_module"><code>module</code></a></li> <li><a href="#globals_process"><code>process</code></a></li> <li><a href="#globals_queuemicrotask_callback"><code>queueMicrotask(callback)</code></a></li> <li><a href="#globals_require"><code>require()</code></a></li> <li><a href="#globals_setimmediate_callback_args"><code>setImmediate(callback[, ...args])</code></a></li> <li><a href="#globals_setinterval_callback_delay_args"><code>setInterval(callback, delay[, ...args])</code></a></li> <li><a href="#globals_settimeout_callback_delay_args"><code>setTimeout(callback, delay[, ...args])</code></a></li> <li><a href="#globals_textdecoder"><code>TextDecoder</code></a></li> <li><a href="#globals_textencoder"><code>TextEncoder</code></a></li> <li><a href="#globals_url"><code>URL</code></a></li> <li><a href="#globals_urlsearchparams"><code>URLSearchParams</code></a></li> <li><a href="#globals_webassembly"><code>WebAssembly</code></a></li> </ul> </li> </ul> </div> <div id="apicontent"> <h1>Global objects<span><a class="mark" href="#globals_global_objects" id="globals_global_objects">#</a></span></h1> <!--introduced_in=v0.10.0--> <!-- type=misc --> <p>These objects are available in all modules. The following variables may appear to be global but are not. They exist only in the scope of modules, see the <a href="modules.html">module system documentation</a>:</p> <ul> <li><a href="modules.html#modules_dirname"><code>__dirname</code></a></li> <li><a href="modules.html#modules_filename"><code>__filename</code></a></li> <li><a href="modules.html#modules_exports"><code>exports</code></a></li> <li><a href="modules.html#modules_module"><code>module</code></a></li> <li><a href="modules.html#modules_require_id"><code>require()</code></a></li> </ul> <p>The objects listed here are specific to Node.js. There are <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects">built-in objects</a> that are part of the JavaScript language itself, which are also globally accessible.</p> <h2>Class: <code>Buffer</code><span><a class="mark" href="#globals_class_buffer" id="globals_class_buffer">#</a></span></h2> <div class="api_metadata"> <span>Added in: v0.1.103</span> </div><!-- type=global --> <ul> <li>{Function}</li> </ul> <p>Used to handle binary data. See the <a href="buffer.html">buffer section</a>.</p> <h2><code>__dirname</code><span><a class="mark" href="#globals_dirname" id="globals_dirname">#</a></span></h2> <p>This variable may appear to be global but is not. See <a href="modules.html#modules_dirname"><code>__dirname</code></a>.</p> <h2><code>__filename</code><span><a class="mark" href="#globals_filename" id="globals_filename">#</a></span></h2> <p>This variable may appear to be global but is not. See <a href="modules.html#modules_filename"><code>__filename</code></a>.</p> <h2><code>clearImmediate(immediateObject)</code><span><a class="mark" href="#globals_clearimmediate_immediateobject" id="globals_clearimmediate_immediateobject">#</a></span></h2> <div class="api_metadata"> <span>Added in: v0.9.1</span> </div><!--type=global--> <p><a href="timers.html#timers_clearimmediate_immediate"><code>clearImmediate</code></a> is described in the <a href="timers.html">timers</a> section.</p> <h2><code>clearInterval(intervalObject)</code><span><a class="mark" href="#globals_clearinterval_intervalobject" id="globals_clearinterval_intervalobject">#</a></span></h2> <div class="api_metadata"> <span>Added in: v0.0.1</span> </div><!--type=global--> <p><a href="timers.html#timers_clearinterval_timeout"><code>clearInterval</code></a> is described in the <a href="timers.html">timers</a> section.</p> <h2><code>clearTimeout(timeoutObject)</code><span><a class="mark" href="#globals_cleartimeout_timeoutobject" id="globals_cleartimeout_timeoutobject">#</a></span></h2> <div class="api_metadata"> <span>Added in: v0.0.1</span> </div><!--type=global--> <p><a href="timers.html#timers_cleartimeout_timeout"><code>clearTimeout</code></a> is described in the <a href="timers.html">timers</a> section.</p> <h2><code>console</code><span><a class="mark" href="#globals_console" id="globals_console">#</a></span></h2> <div class="api_metadata"> <span>Added in: v0.1.100</span> </div><!-- type=global --> <ul> <li>{Object}</li> </ul> <p>Used to print to stdout and stderr. See the <a href="console.html"><code>console</code></a> section.</p> <h2><code>exports</code><span><a class="mark" href="#globals_exports" id="globals_exports">#</a></span></h2> <p>This variable may appear to be global but is not. See <a href="modules.html#modules_exports"><code>exports</code></a>.</p> <h2><code>global</code><span><a class="mark" href="#globals_global" id="globals_global">#</a></span></h2> <div class="api_metadata"> <span>Added in: v0.1.27</span> </div><!-- type=global --> <ul> <li>{Object} The global namespace object.</li> </ul> <p>In browsers, the top-level scope is the global scope. This means that within the browser <code>var something</code> will define a new global variable. In Node.js this is different. The top-level scope is not the global scope; <code>var something</code> inside a Node.js module will be local to that module.</p> <h2><code>module</code><span><a class="mark" href="#globals_module" id="globals_module">#</a></span></h2> <p>This variable may appear to be global but is not. See <a href="modules.html#modules_module"><code>module</code></a>.</p> <h2><code>process</code><span><a class="mark" href="#globals_process" id="globals_process">#</a></span></h2> <div class="api_metadata"> <span>Added in: v0.1.7</span> </div><!-- type=global --> <ul> <li>{Object}</li> </ul> <p>The process object. See the <a href="process.html#process_process"><code>process</code> object</a> section.</p> <h2><code>queueMicrotask(callback)</code><span><a class="mark" href="#globals_queuemicrotask_callback" id="globals_queuemicrotask_callback">#</a></span></h2> <div class="api_metadata"> <span>Added in: v11.0.0</span> </div><!-- type=global --> <ul> <li><code>callback</code> {Function} Function to be queued.</li> </ul> <p>The <code>queueMicrotask()</code> method queues a microtask to invoke <code>callback</code>. If <code>callback</code> throws an exception, the <a href="process.html#process_process"><code>process</code> object</a> <code>'uncaughtException'</code> event will be emitted.</p> <p>The microtask queue is managed by V8 and may be used in a similar manner to the <a href="process.html#process_process_nexttick_callback_args"><code>process.nextTick()</code></a> queue, which is managed by Node.js. The <code>process.nextTick()</code> queue is always processed before the microtask queue within each turn of the Node.js event loop.</p> <pre><code class="language-js">// Here, `queueMicrotask()` is used to ensure the 'load' event is always // emitted asynchronously, and therefore consistently. Using // `process.nextTick()` here would result in the 'load' event always emitting // before any other promise jobs. DataHandler.prototype.load = async function load(key) { const hit = this._cache.get(url); if (hit !== undefined) { queueMicrotask(() => { this.emit('load', hit); }); return; } const data = await fetchData(key); this._cache.set(url, data); this.emit('load', data); }; </code></pre> <h2><code>require()</code><span><a class="mark" href="#globals_require" id="globals_require">#</a></span></h2> <p>This variable may appear to be global but is not. See <a href="modules.html#modules_require_id"><code>require()</code></a>.</p> <h2><code>setImmediate(callback[, ...args])</code><span><a class="mark" href="#globals_setimmediate_callback_args" id="globals_setimmediate_callback_args">#</a></span></h2> <div class="api_metadata"> <span>Added in: v0.9.1</span> </div><!-- type=global --> <p><a href="timers.html#timers_setimmediate_callback_args"><code>setImmediate</code></a> is described in the <a href="timers.html">timers</a> section.</p> <h2><code>setInterval(callback, delay[, ...args])</code><span><a class="mark" href="#globals_setinterval_callback_delay_args" id="globals_setinterval_callback_delay_args">#</a></span></h2> <div class="api_metadata"> <span>Added in: v0.0.1</span> </div><!-- type=global --> <p><a href="timers.html#timers_setinterval_callback_delay_args"><code>setInterval</code></a> is described in the <a href="timers.html">timers</a> section.</p> <h2><code>setTimeout(callback, delay[, ...args])</code><span><a class="mark" href="#globals_settimeout_callback_delay_args" id="globals_settimeout_callback_delay_args">#</a></span></h2> <div class="api_metadata"> <span>Added in: v0.0.1</span> </div><!-- type=global --> <p><a href="timers.html#timers_settimeout_callback_delay_args"><code>setTimeout</code></a> is described in the <a href="timers.html">timers</a> section.</p> <h2><code>TextDecoder</code><span><a class="mark" href="#globals_textdecoder" id="globals_textdecoder">#</a></span></h2> <div class="api_metadata"> <span>Added in: v11.0.0</span> </div><!-- type=global --> <p>The WHATWG <code>TextDecoder</code> class. See the <a href="util.html#util_class_util_textdecoder"><code>TextDecoder</code></a> section.</p> <h2><code>TextEncoder</code><span><a class="mark" href="#globals_textencoder" id="globals_textencoder">#</a></span></h2> <div class="api_metadata"> <span>Added in: v11.0.0</span> </div><!-- type=global --> <p>The WHATWG <code>TextEncoder</code> class. See the <a href="util.html#util_class_util_textencoder"><code>TextEncoder</code></a> section.</p> <h2><code>URL</code><span><a class="mark" href="#globals_url" id="globals_url">#</a></span></h2> <div class="api_metadata"> <span>Added in: v10.0.0</span> </div><!-- type=global --> <p>The WHATWG <code>URL</code> class. See the <a href="url.html#url_class_url"><code>URL</code></a> section.</p> <h2><code>URLSearchParams</code><span><a class="mark" href="#globals_urlsearchparams" id="globals_urlsearchparams">#</a></span></h2> <div class="api_metadata"> <span>Added in: v10.0.0</span> </div><!-- type=global --> <p>The WHATWG <code>URLSearchParams</code> class. See the <a href="url.html#url_class_urlsearchparams"><code>URLSearchParams</code></a> section.</p> <h2><code>WebAssembly</code><span><a class="mark" href="#globals_webassembly" id="globals_webassembly">#</a></span></h2> <div class="api_metadata"> <span>Added in: v8.0.0</span> </div><!-- type=global --> <ul> <li>{Object}</li> </ul> <p>The object that acts as the namespace for all W3C <a href="https://webassembly.org">WebAssembly</a> related functionality. See the <a href="https://developer.mozilla.org/en-US/docs/WebAssembly">Mozilla Developer Network</a> for usage and compatibility.</p> <!-- API END --> </div> </div> </div> </body> </html>