Call Back Function

Hello there,

I happened to come up with a simplified concept of call back function. It seemed to me somewhat complicated sometimes. I think some of you might also come up against the same complication. It’s just what came into my mind. If you find any inconsistency, please let me know. I’ll be happy to hear from you. Now let me explain it.

Generally, first we declare/create a function. And then we call it elsewhere. Like so.

// declare/create a callmeLateron () function

function callmeLateron(a, b){

    return a + b;

}

// call the function

callmeLateron(2, 3);

But when we call the function first and then declare it elsewhere, it’s called a call back function. Like so.

function operation(a, b){

    var c = a + b;

    var d = a - b;

      // call declaremeLateron function

    declaremeLateron(c, d); // call back function

}

// declare declaremeLateron function

function declaremeLateron(c, d){

    console.log(c, d); // 15, 5

}

// call operation function

operation(10, 5);

Here we, first, call the ‘declarelmeLateron’ function within ‘operation’ function. And later on we declare the ‘declaremeLateron’ function.

So, declaremeLateron(c,d) is a call back function.

In a word,

declare first, call next = simple function

call first, declare next = call back function

That’s it. As simple as that. :D

See you.