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How to return value from anonymous function in js

I would like to return a value from an anonymous function. How do I assign the return value to the $ id variable in the below code?

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

 //$id in this scope should be equal 4
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2 answers


One thing you should know that you are working here with asynchronous actions. Let the numeric strings be in execution order (n means some large number much later)

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

What you did was hooked up to a listener. For now, no click will happen - it will happen when someone clicks. This way you will access it after clicking. You can do two things:

  • Declare var in the scope above.
  • Direct value for callback

1) Example 1



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

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

You can also do some research on $ watch, especially Angular works a lot for you here.

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You need to specify what to do when the function or asyn operation has been reached, so usually returning when using callbacks is just another callback ...

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

and you will use the code in yourself like this:



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

This is how callbacks return values ​​to the outer scope.

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