What's the difference b/w old and new javascript function syntax?

Question

Possible Duplicate:
JavaScript: var functionName = function() {} vs function functionName() {}

How are Foo and Bar any different ?

If objects were only functions, why was this new syntax introduced ? (Foo).

var Foo = function(arg) {
    this.attr = arg;
};

function Bar (arg)  {
    this.attr = arg;
}


/*
>>> f = new Foo(3)
Object { attr=3}
>>> f.attr
3
>>> b = new Bar(40)
Bar { attr=40}
>>> b.attr
40
*/

A fair amount of documentation I'v read proposes the first syntaxe, but the second one seems to work just as well.

[Allow John Resig to clear this up for you](http://ejohn.org/apps/learn/#9). — Eliran Malka, Jul 23 '12 at 14:56

score -1 · Answer 1 · answered Jul 23 '12 at 14:57

-1

The difference come here:

console.log(typeof foo); //'function'
function foo() {
}

console.log(typeof bar); //'undefined'
var bar = function () {
}

answered Jul 23 '12 at 14:57

Minko Gechev

23,174
7
57
66

While that demonstrates an effect of the primary difference, it doesn't explain it at all. – Quentin Jul 23 '12 at 15:02
I think that the example is clear enough and there's not need for further explanation. – Minko Gechev Jul 23 '12 at 15:09

What's the difference b/w old and new javascript function syntax?

1 Answers1