Global Objects | Node.js v7.8.0 Documentation

Node.js

- About these Docs
- Usage & Example

- Assertion Testing
- Buffer
- C/C++ Addons
- Child Processes
- Cluster
- Command Line Options
- Console
- Crypto
- Debugger
- DNS
- Domain
- Errors
- Events
- File System
- Globals
- HTTP
- HTTPS
- Modules
- Net
- OS
- Path
- Process
- Punycode
- Query Strings
- Readline
- REPL
- Stream
- String Decoder
- Timers
- TLS/SSL
- Tracing
- TTY
- UDP/Datagram
- URL
- Utilities
- V8
- VM
- ZLIB

- GitHub Repo & Issue Tracker
- Mailing List

# Global Objects#

These objects are available in all modules. Some of these objects aren't actually in the global scope but in the module scope - this will be noted.

The objects listed here are specific to Node.js. There are a number of built-in objects that are part of the JavaScript language itself, which are also globally accessible.

## Class: Buffer#

Added in: v0.1.103

- <Function>

Used to handle binary data. See the buffer section.

## __dirname#

Added in: v0.1.27

- <string>

The directory name of the current module. This the same as the `path.dirname()` of the `__filename`.

`__dirname` is not actually a global but rather local to each module.

Example: running `node example.js` from `/Users/mjr`

    console.log(__dirname);
    // Prints: /Users/mjr
    console.log(path.dirname(__filename));
    // Prints: /Users/mjr

## __filename#

Added in: v0.0.1

- <string>

The file name of the current module. This is the resolved absolute path of the current module file.

For a main program this is not necessarily the same as the file name used in the command line.

See `__dirname` for the directory name of the current module.

`__filename` is not actually a global but rather local to each module.

Examples:

Running `node example.js` from `/Users/mjr`

    console.log(__filename);
    // Prints: /Users/mjr/example.js
    console.log(__dirname);
    // Prints: /Users/mjr

Given two modules: `a` and `b`, where `b` is a dependency of `a` and there is a directory structure of:

- `/Users/mjr/app/a.js`
- `/Users/mjr/app/node_modules/b/b.js`

References to `__filename` within `b.js` will return `/Users/mjr/app/node_modules/b/b.js` while references to `__filename` within `a.js` will return `/Users/mjr/app/a.js`.

## clearImmediate(immediateObject)#

Added in: v0.9.1

`clearImmediate` is described in the timers section.

## clearInterval(intervalObject)#

Added in: v0.0.1

`clearInterval` is described in the timers section.

## clearTimeout(timeoutObject)#

Added in: v0.0.1

`clearTimeout` is described in the timers section.

## console#

Added in: v0.1.100

- <Object>

Used to print to stdout and stderr. See the `console` section.

## exports#

Added in: v0.1.12

A reference to the `module.exports` that is shorter to type. See module system documentation for details on when to use `exports` and when to use `module.exports`.

`exports` is not actually a global but rather local to each module.

See the module system documentation for more information.

## global#

Added in: v0.1.27

- <Object> The global namespace object.

In browsers, the top-level scope is the global scope. That means that in browsers if you're in the global scope `var something` will define a global variable. In Node.js this is different. The top-level scope is not the global scope; `var something` inside an Node.js module will be local to that module.

## module#

Added in: v0.1.16

- <Object>

A reference to the current module. In particular `module.exports` is used for defining what a module exports and makes available through `require()`.

`module` is not actually a global but rather local to each module.

See the module system documentation for more information.

## process#

Added in: v0.1.7

- <Object>

The process object. See the `process` object section.

## require()#

Added in: v0.1.13

- <Function>

To require modules. See the Modules section. `require` is not actually a global but rather local to each module.

### require.cache#

Added in: v0.3.0

- <Object>

Modules are cached in this object when they are required. By deleting a key value from this object, the next `require` will reload the module. Note that this does not apply to native addons, for which reloading will result in an Error.

### require.extensions#

Added in: v0.3.0Deprecated since: v0.10.6

    Stability: 0 - Deprecated

- <Object>

Instruct `require` on how to handle certain file extensions.

Process files with the extension `.sjs` as `.js`:

    require.extensions['.sjs'] = require.extensions['.js'];

Deprecated In the past, this list has been used to load non-JavaScript modules into Node.js by compiling them on-demand. However, in practice, there are much better ways to do this, such as loading modules via some other Node.js program, or compiling them to JavaScript ahead of time.

Since the module system is locked, this feature will probably never go away. However, it may have subtle bugs and complexities that are best left untouched.

Note that the number of file system operations that the module system has to perform in order to resolve a `require(...)` statement to a filename scales linearly with the number of registered extensions.

In other words, adding extensions slows down the module loader and should be discouraged.

### require.resolve()#

Added in: v0.3.0

Use the internal `require()` machinery to look up the location of a module, but rather than loading the module, just return the resolved filename.

## setImmediate(callback[, ...args])#

Added in: v0.9.1

`setImmediate` is described in the timers section.

## setInterval(callback, delay[, ...args])#

Added in: v0.0.1

`setInterval` is described in the timers section.

## setTimeout(callback, delay[, ...args])#

Added in: v0.0.1

`setTimeout` is described in the timers section.