Return an object key only if value is true

Question

How do i return an object key name only if the value of it is true?

I\'m using underscore and the only thing i see is how to return keys which is easy, i want to avo

Answer 1

If you're trying to combine filtering and iterating over an object you're usually after _.reduce (the Swiss Army Knife iterator):

var trues = _(obj).reduce(function(trues, v, k) {
    if(v === true)
        trues.push(k);
    return trues;
}, [ ]);

Demo: http://jsfiddle.net/ambiguous/2et6T/