Modifying Object.prototype is an extremely bad practice. jQuery is not supported on any page where this occurs.

I'm going to re-open this so that we can try and tackle it in a future release.

Related discussions:

http://groups.google.com/group/jquery-dev/browse_thread/thread/22c8d4a94812c986/

http://groups.google.com/group/jquery-dev/browse_thread/thread/7e9015540341a17c/

Fix should be easy:

for (var i in O) {
    if (!O.hasOwnProperty(i)) { continue; }
    // other code stays unchanged
}

The only two problems are:

1.) IE 5.0 and older don't support {}.hasOwnProperty() - but this can be implemented using Object.prototype ...

2.) Find all the for-in-loops ;)

I don't think this was meant to be changed to 'new' - switching back to open.

Additional test: http://jsfiddle.net/rwaldron/F8UKY/2/

#7977 is a duplicate of this ticket.

Yet another test case (extracted from 7977)

Replying to [comment:6 Cheatah]:

Fix should be easy:

> for (var i in O) {
>     if (!O.hasOwnProperty(i)) { continue; }
>     // other code stays unchanged
> }
> 

The only two problems are: 1.) IE 5.0 and older don't support {}.hasOwnProperty() - but this can be implemented using Object.prototype ... 2.) Find all the for-in-loops ;)

For 1.), it's as simple as adding a jQuery-local function for hasOwnProperty (or even $.hasOwnProperty), similar to this:

function hasOwnProperty(object, prop) {
    if (Object.prototype.hasOwnProperty) {
        return Object.prototype.hasOwnProperty.call(object, prop);
    }
    
    return true; // or a suitable implementation, if one can be implemented easily -- I had seen a good one once, but can't find it now that I need it
}

Then, use this function in $.each, and convert all other for-in loops to use $.each instead (or use this function in each of those, if that's preferable). Win-win?

This isn't something that we're going to fix:

http://docs.jquery.com/Won%27t_Fix

#11053 is a duplicate of this ticket.

#11605 is a duplicate of this ticket.

#12090 is a duplicate of this ticket.

#13671 is a duplicate of this ticket.

#13731 is a duplicate of this ticket.

#15208 is a duplicate of this ticket.