returning from javascript function without waiting for called function

Question

I have javascript function1 which calls another function2 my requirement is that function 1 should not wait for function 2 execution.

My function 2 calls ajax which makes process delayed which causes user to wait until my function2 returns. is there any i can return from function1 as soon as function1 calls function2 ?

Use setTimeout to call the function2, and the function would return. — Aravind
– Aravind, Commented Nov 22, 2014 at 10:28
Actually calling ajax doesn't make the process delay if you use the asynchronous version of it. — Sampath Liyanage
– Sampath Liyanage, Commented Nov 22, 2014 at 10:30

Aravind · Accepted Answer · 2014-11-22 10:39:45Z

3

You can do something like this:

function f()
{
 f1();
 console.log("I'm impatient, can't wait for f1");
}
function f1()
{
 setTimeout(function(){f2();},0);
}
function f2()
{
 // your function which takes a long time to run
 for(var i =0;i<10000000;i++);
 console.log("I'm f2 and I'm finally done!");
}
f();

How does this work?

When you call f1(), it has the setTimeout function. setTimeout sees the function and puts it on the event queue, and the statement is done. Program control returns to f() and "I'm impatient, can't wait for f1" is printed, and then when f2 is executed completely, "I'm f2 and I'm finally done!" is printed.

edited Nov 22, 2014 at 10:39

answered Nov 22, 2014 at 10:30

Aravind

3,2094 gold badges25 silver badges37 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

user663031 Over a year ago

Minor point, but it would be completely equivalent to say setTimeout(f2, 0).

Aravind Over a year ago

@torazaburo: Yes, true. This is a legitimate way to achieve what OP wants, I wish people would comment and explain the downvote :)

Piotr Gajdowski Over a year ago

Even though old post, it helped me solve my problem, thanks!

Collectives™ on Stack Overflow

returning from javascript function without waiting for called function

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related