How to find index of object in a JavaScript array with jQuery

Question

I am trying to find the index of an object in an array in jquery. I cannot use jQuery.inArray because i want to match objects on a certain property. I am using:

Answer 1

Not sure why each() doesn't work for you:

BROKEN -- SEE FIX BELOW

function check(arr, closure)
{
    $.each(arr,function(idx, val){
       // Note, two options are presented below.  You only need one.
       // Return idx instead of val (in either case) if you want the index
       // instead of the value.

       // option 1.  Just check it inline.
       if (val['Foo'] == 'Bar') return val;

       // option 2.  Run the closure:
       if (closure(val)) return val;
    });
    return -1;
}

---

Additional example for Op comments.

Array.prototype.UContains = function(closure)
{
    var i, pLen = this.length;
    for (i = 0; i < pLen; i++)
    {
       if (closure(this[i])) { return i; } 
    }
    return -1;
}
// usage:
// var closure = function(itm) { return itm.Foo == 'bar'; };
// var index = [{'Foo':'Bar'}].UContains(closure);

---

Ok, my first example IS HORKED. Pointed out to me after some 6 months and multiple upvotes. : )

Properly, check() should look like this:

function check(arr, closure)
{
    var retVal = false; // Set up return value.
    $.each(arr,function(idx, val){
       // Note, two options are presented below.  You only need one.
       // Return idx instead of val (in either case) if you want the index
       // instead of the value.

       // option 1.  Just check it inline.
       if (val['Foo'] == 'Bar') retVal = true; // Override parent scoped return value.

       // option 2.  Run the closure:
       if (closure(val)) retVal = true;
    });
    return retVal;
}

The reason here is pretty simple... the scoping of the return was just wrong.

At least the prototype object version (the one I actually checked) worked.

Thanks Crashalot. My bad.