How to change the context of a function in javascript

Question

I\'m trying to understand why in javascript, you might want to change the context of a function. I\'m looking for a real world example or something which will help me unders

Answer 1

jQuery makes use of it to good effect:

$('a').each(function() {
    // "this" is an a element - very useful
});

The actual jQuery code looks like this:

for ( name in object ) {
    if ( callback.call( object[ name ], name, object[ name ] ) === false ) {
        break;
    }
}

If it just did callback( name, object[ name ] ) then this wouldn't be set to the current object in your iterator and you'd have to use the parameter instead. Basically it just makes things easier.