$.each wraps values into objects

[joel.dumas@…]

Using $.each to iterate over an array of values (tested with strings) wraps them into objects (i.e. what you get with new String("xyz")).

This is very subtle, but there are important differences between the two and when it bites you you can have a very hard time figuring out what happens. For instance, the following assertion is wrong: $.each(array, function(index) { array[index] === this })

As another example with jQuery 1.6, $("<div>").text("abc") works, but $("<div>").text(new String("abc")) does not. When this is done with a local variable the difference between the two is very hard to spot. (Note that the $.text function has been fixed to accept String objects since then and this particular example works in jQuery 1.8. -- But other pieces of code could be affected in a similar way.)

The minimal test case: ​http://jsfiddle.net/7XkvP/2/

[Rick Waldron]

From the docs:

(The value can also be accessed through the this keyword, but Javascript will always wrap the this value as an Object even if it is a simple string or number value.) The method returns its first argument, the object that was iterated.

​http://api.jquery.com/jquery.each/

[joel.dumas@…]

Didn't notice this remark. It's a good gotcha (and the SignalR devs fell for it).

But if javascript always wraps this into an object I suppose there's nothing we can do about it :(

JS is really a language full of traps :(

[ajpiano]

If you just use $.each( arr, function( index, elem ) { }), the second arg is always what you expect.

[dmethvin]

#13202 is a duplicate of this ticket.