What is function closure?

[LAN MIND]

?

[liamgegan]

function your_function()
{
var closure='hello function';
return function()
{
alert(cosure);
}
}

On Jan 27, 4:24 pm, LAN MIND <[e-mail]:

?

[liamgegan]

sorry, that one line should be:
alert(closure);

That should answer your question if it were about how to make a
closure. If your question was actually asking what it was (in a what
does it do sense), then a closure is a function that has access to
various temporary variables that were created in the same scope that
they were (see example below).

On Jan 27, 7:26 pm, "[e-mail]" <[e-mail]:

function your_function()
{
var closure='hello function';
return function()
{
alert(cosure);
}

}

On Jan 27, 4:24 pm, LAN MIND <[e-mail]:

?

[Marcio Faustino]

From the "javascript: The Definitive Guide" book:

«JavaScript functions are a combination of code to be executed and the
scope in which to execute them. This combination of code and scope is
known as a closure (...) All JavaScript functions are closures. These
closures are only interesting, however, in the case discussed above:
when a nested function is exported outside the scope in which it is
defined. When a nested function is used in this way, it is often
explicitly called a closure.»

[timothytoe]

On Jan 27, 3:01 am, Marcio Faustino <[e-mail]:

From the "javascript: The Definitive Guide" book:

«JavaScript functions are a combination of code to be executed and the
scope in which to execute them. This combination of code and scope is
known as a closure (...) All JavaScript functions are closures. These
closures are only interesting, however, in the case discussed above:
when a nested function is exported outside the scope in which it is
defined. When a nested function is used in this way, it is often
explicitly called a closure.»

One common use is when SetTimeout is called. Suppose you set up a
timer which will do something in 10 seconds. You don't have to worry
about keeping the scope around to be used because the closure holds on
to the scope long enough for the SetTimeout to use it.