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I would like to return value from anonymous function. How can I assign returned value to $id variable in below code ?

$(document).on("click", '.delete-ponent', function(e) {
     return 4;
 });

 //$id in this scope should be equal 4

I would like to return value from anonymous function. How can I assign returned value to $id variable in below code ?

$(document).on("click", '.delete-ponent', function(e) {
     return 4;
 });

 //$id in this scope should be equal 4

• javascript
• anonymous-function

Share Improve this question Follow edited Dec 2, 2014 at 13:21 Thomas Shelby asked Dec 2, 2014 at 13:13 Thomas ShelbyThomas Shelby 1,37055 gold badges2020 silver badges3939 bronze badges 3

• You cannot assign it to anything before the click has happened. No, you cannot return a value from an asynchronous callback. – Bergi Commented Dec 2, 2014 at 13:15
• Event callback will be called on click, but you can't assign its result. However you can make some assignments inside of it. – dfsq Commented Dec 2, 2014 at 13:16
• What are you going to do with the return value? – Sampath Liyanage Commented Dec 4, 2014 at 14:51

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2 Answers 2

Sorted by: Reset to default 4

You need to specify what to do when asyn function or operation is reached, so usually a return when using callbacks is another callback...

function aux(param1, callback){
    // do whatever...
    $(document).on("click", param1, function(e) {
        // return 4;
        callback(4);
    });
}

and you would use it in you code as following:

// your context..
// operations 1.. 2..
aux('.delete-ponent', function(theReturnedValue){
    console.log(theReturnedValue); // 4
});

This is how callbacks 'return' values to an outer scope.

One thing you have to be aware that you work here with asynchronous actions. Let's number lines in order of exaction (n means some high number far far later)

1]    $(document).on("click", '.delete-ponent', function(e) {
n+1]    return 4;
      });
2]    console.log('here');

What you did was attached listener to click. Click won't happen at the moment - it will happen when someone clicks. Therefore you will have access to it after click happens. You can do two things:

1. Declare var in scope above.
2. Forward value to callback

1) Example 1

var myValue = 0;
$(document).on("click", '.delete-ponent', function(e) {
     myValue = 4;
});

function abc() {
  console.log('myValue is equal to ' + myValue);
}

// if that line happen before clicking, value will be still 0
execture somewhen abc();

2) Example 2

$(document).on("click", '.delete-ponent', function(e) {
     doSomethingWithValue(4);
});

function doSomethingWithValue() {
  console.log('myValue is equal to ' + myValue);
}

You can also investigate $watch, especially Angular does here a lot work for you.

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