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Node.js v6.12.3 Documentation
Table of Contents
- Global Objects
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#
Used to handle binary data. See the buffer section.
__dirname#
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#
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)#
clearImmediate
is described in the timers section.
clearInterval(intervalObject)#
clearInterval
is described in the timers section.
clearTimeout(timeoutObject)#
clearTimeout
is described in the timers section.
console#
Used to print to stdout and stderr. See the console
section.
exports#
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#
- <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#
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#
The process object. See the process
object section.
require()#
To require modules. See the Modules section. require
is not actually a
global but rather local to each module.
require.cache#
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#
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.
require.resolve()#
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])#
setImmediate
is described in the timers section.
setInterval(callback, delay[, ...args])#
setInterval
is described in the timers section.
setTimeout(callback, delay[, ...args])#
setTimeout
is described in the timers section.