Global Objects
- {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 will define a global
variable. In Node this is different. The top-level scope is not the global
scope; var something
inside a Node module will be local to that module.
process
The process object. See the section.
console
- {Object}
Used to print to stdout and stderr. See the section.
Class: Buffer
- {Function}
Used to handle binary data. See the
- {Function}
To require modules. See the Modules section. require
isn’t actually a
global but rather local to each module.
Use the internal require()
machinery to look up the location of a module,
but rather than loading the module, just return the resolved filename.
- {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.
- {Object}
Instruct require
on how to handle certain file extensions.
Process files with the extension .sjs
as .js
:
Deprecated In the past, this list has been used to load
non-JavaScript modules into Node by compiling them on-demand.
However, in practice, there are much better ways to do this, such as
loading modules via some other Node program, or compiling them to
JavaScript ahead of time.
__filename
- {String}
The filename of the code being executed. This is the resolved absolute path
of this code file. For a main program this is not necessarily the same
filename used in the command line. The value inside a module is the path
to that module file.
Example: running node example.js
from
__filename
isn’t actually a global but rather local to each module.
__dirname
- {String}
The name of the directory that the currently executing script resides in.
Example: running node example.js
from /Users/mjr
__dirname
isn’t actually a global but rather local to each module.
module
- {Object}
A reference to the current module. In particularmodule.exports
is used for defining what a module exports and makes
available through require()
.
module
isn’t actually a global but rather local to each module.
See the module system documentation for more information.
A reference to the module.exports
that is shorter to type.
See for details on when to use and
when to use module.exports
.
See the module system documentation for more information.
See the for more information.
setTimeout(cb, ms)
Run callback cb
after at least ms
milliseconds. The actual delay depends
on external factors like OS timer granularity and system load.
The timeout must be in the range of 1-2,147,483,647 inclusive. If the value is
outside that range, it’s changed to 1 millisecond. Broadly speaking, a timer
cannot span more than 24.8 days.
Returns an opaque value that represents the timer.
clearTimeout(t)
Stop a timer that was previously created with setTimeout()
. The callback will
not execute.
setInterval(cb, ms)
Run callback cb
repeatedly every ms
milliseconds. Note that the actual
interval may vary, depending on external factors like OS timer granularity and
system load. It’s never less than ms
but it may be longer.
The interval must be in the range of 1-2,147,483,647 inclusive. If the value is
outside that range, it’s changed to 1 millisecond. Broadly speaking, a timer
cannot span more than 24.8 days.
Returns an opaque value that represents the timer.
Stop a timer that was previously created with . The callback
will not execute.