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

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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:

jQuery.inObjectArray = function(arr, func)
    {
        for(var i=0;i<arr.length;i++)
            if(func(arr[i]))
                return i;
        return -1;
    }

and then calling:

jQuery.inObjectArray([{Foo:"Bar"}], function(item){return item.Foo == "Bar"})

Is there a built in way?

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:

jQuery.inObjectArray = function(arr, func)
    {
        for(var i=0;i<arr.length;i++)
            if(func(arr[i]))
                return i;
        return -1;
    }

and then calling:

jQuery.inObjectArray([{Foo:"Bar"}], function(item){return item.Foo == "Bar"})

Is there a built in way?

• javascript
• jquery
• arrays

Share Improve this question Follow edited Sep 8, 2011 at 10:50 Luke Girvin 13.5k1010 gold badges6767 silver badges8585 bronze badges asked May 24, 2011 at 9:00 DanielDaniel 2,38133 gold badges2727 silver badges3535 bronze badges 3

• Could be me, but is there any jQuery specific code in your example? – gnur Commented May 24, 2011 at 9:04
• Do you only want the index or the object itself? – Felix Kling Commented May 24, 2011 at 9:04
• I want the index i think i can get the object with grep. – Daniel Commented May 24, 2011 at 9:06

Add a ment  | 

1 Answer 1

Sorted by: Reset to default 7

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 ments.

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.

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