which is the better way of defining a function?

Question

Is there any difference between them ? I've been using both the ways but do not know which one does what and which is better?

function abc(){

    // Code comes here.
}

abc = function (){

    // Code comes here.
}

Is there any difference between defining these functions ? Something like i++ and ++i ?

repeated Question: http://stackoverflow.com/questions/336859/javascript-var-functionname-function-vs-function-functionname — kishoredbn, Jun 13 '13 at 11:16
Why did you add the `html` tag again? This question has nothing to do with HTML! — Felix Kling, Jun 13 '13 at 11:29
that's becuase people may consider this question to that of java - which uses object oriented approach... — Janak, Jun 13 '13 at 11:31
The question is already tagged `javascript`. It's clear that it has nothing to do with Java. If someone does not know that there is a difference between JavaScript and Java, they shouldn't be programming. — Felix Kling, Jun 13 '13 at 11:31

Darren · Accepted Answer · 2013-06-13T11:32:26.057

7

function abc(){

    // Code comes here.
}

Will be hoisted.

abc = function (){

    // Code comes here.
}

Will not be hoisted.

For instance if you did:

 abc(); 
 function abc() { }

The code will run as abc is hoisted to the top of the enclosing scope.

If you however did:

  abc();
  var abc = function() { }

abc is declared but has no value and therefore cannot be used.

As to which is better is more of a debate of programming style.

http://www.sitepoint.com/back-to-basics-javascript-hoisting/

edited Jun 13 '13 at 11:32

answered Jun 13 '13 at 11:15

Darren

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Nitpick: *"Then `abc` is not yet declared and cannot be used."* Variable declarations are hoisted too, so the variable is declared, but it has no value yet. – Felix Kling Jun 13 '13 at 11:30
@FelixKling - updated. Cheers. – Darren Jun 13 '13 at 11:32

score 1 · Answer 2 · answered Jun 13 '13 at 11:20

Short answer: none.

You are putting the function in the global namespace. Anyone can access this, anyone can overwrite this.

The standard more safe way to do it is wrap everything in a self calling function:

(function(){
    // put some variables, flags, constants, whatever here.
    var myVar = "one";

    // make your functions somewhere here
    var a = function(){
        // Do some stuff here

        // You can access your variables here, and they are somehow "private"
        myVar = "two";
    };


    var b = function() {

        alert('hi');
    };

    // You can make b public by doing this
    return {
        publicB: b
    };
})();

which is the better way of defining a function?

2 Answers2