declare function name in object, Why?

Question

Was working on some js code performance and saw this approach:

window.sample = {

    foo: function foo(a,b){
       // code goes here
    }

    bar: function bar(a,b){
       // code goes here
    }

}

is there any reason why you would decelerate the function name after the word "function" ?

dose it help to debug?

is it good or bad or just unnecessary?

@JosephtheDreamer Oh, right. (The "code performance" context was a red herring.) — JJJ, May 23 '12 at 13:08

score 4 · Answer 1 · answered May 23 '12 at 13:07

The only reason would be that you can use the function itself from within the function without a reference to the object:

foo: function foo(a,b){
   return a > 0 ? a + foo(a-1,b) : b;
}

Note howeever that support for named function literals is not consistent across browsers, so you should really avoid using it.

score 1 · Accepted Answer · answered May 23 '12 at 13:07

1

instead of assigning an anonymous function to the foo and bar properties, they are assigning named functions.

it can be helpful for debugging: the only difference this makes, that i know of, is that you will see the names of the functions show up in the call stack instead of "javascript anonymous function"

answered May 23 '12 at 13:07

jbabey

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Is it not enough if you do console.log(sample); then? – Endless May 23 '12 at 13:09
@Endless i think @jbabey meant stack tracing during errors. If it didn't have a name, the console would say something like `anonymous function` since it does not have a name. – Joseph May 23 '12 at 13:11
@Joseph ah, i understand – Endless May 23 '12 at 13:12

Tim Down · Answer 3 · 2012-05-23T15:47:35.550

It's a named function expression. The name of the function is only available as a variable within the function itself. This can be useful for recursion, for example:

var obj = {
    foo: function foo(node) {
        // Do something to node

        var childNode = node.firstChild;
        while (childNode) {
            foo(childNode);
            childNode = childNode.nextSibling;
        }
    }
};

The name of the function is also available in most browsers via the non-standard name property of the function, which can help identify functions while debugging or examining stack traces.

IE < 9 has a flawed implementation, so you need to exercise care when using it. Full details can be found in Juriy Zaytsev's excellent article on the subject.

declare function name in object, Why?

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