js equiv of php's foreach($arr as $k=>$v)

Question

Lets be clear, I'm not asking for for(var i in list) I want the key assigned to a variable as well.

score 8 · Accepted Answer · answered Sep 24 '10 at 02:14

8

The key is, actually, the only thing that gets assigned:

var value;
for(var key in list) {
    value = list[key];
    // do something with key, value
}

answered Sep 24 '10 at 02:14

Matchu

You are right indeed. Why I believed the opposite to be true, nfi. Thanks! – lsl Sep 24 '10 at 02:21

score 1 · Answer 2 · answered Sep 24 '10 at 02:21

1

Javascript doesn't have this functionality built into the language. The closest it comes is the for (...in...) syntax that you've already rejected.

Look to your javascript library for this functionality. For example, the ever ubiquitous jQuery's each().

answered Sep 24 '10 at 02:21

Alana Storm

1

I think he only rejected it because he misunderstood it. – Matchu Sep 24 '10 at 02:24
1

True, but for (...in...) can introduce some weird scoping bugs to your code, and then there's the whole hasOwnProperty weirdness. Plenty of reasons to avoid it even if you understand it. – Alana Storm Sep 24 '10 at 16:49
@AlanStorm Just came across a post explaining your concerns quite well, I understand it now! http://stackoverflow.com/questions/1885317/strange-behavior-in-javascript-enhanced-for-in-loop/1885365#1885365 – lsl Apr 16 '12 at 22:23

2 Answers2