declare function name in object, Why? [duplicate]

Answer 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"

Answer 2

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.

Answer 3

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.