Javascript: Create call back for function

Question

My requirement is very simple.

 subscribePresence();
 getValidationData();

getValidationData() must be called only when subscribePresence(); finishes its execution. is there any way of doing it ?

It seems like you know what a callback is, so what have you tried? — vol7ron
– vol7ron, Commented May 5, 2016 at 5:09
That's exactly how Javascript works. The code you have supplied will guarantee that subscribePresence(); finishes executing before getValidationData(); is called. JavaScript executes code in order. Whether or not subscribePresence(); starts some other asynchronous task has nothing to do with it finishing its execution. — Paul
– Paul, Commented May 5, 2016 at 5:09
Possible duplicate of Create a custom callback in JavaScript — Matt Komarnicki
– Matt Komarnicki, Commented May 5, 2016 at 5:14
Show us the code for subscribePresence() so we can see whether it is asynchronous or not and, if so, how to know when it is done with its work. — jfriend00
– jfriend00, Commented May 5, 2016 at 5:18

Guruprasad J Rao · Accepted Answer · 2016-05-05 05:04:41Z

1

Pass getValidationData(); as callback function into first function.

Ex:

function subscribePresence(callback){
  //do your stuffs
  callback();
}

Now call your subscribePresence() as below

subscribePresence(getValidationData);

answered May 5, 2016 at 5:04

Guruprasad J Rao

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