What's the fastest way to iterate over an object's properties in Javascript?

Question

I know that I can iterate over an object\'s properties like this:

for (property in object)
{
    // do stuff
}

I also know that the fastest

Answer 1

Explicit use of Iterator in JavaScript 1.7+ might be faster or slower. Of course this will only iterate an object's own properties. The catch statement also might be faster with ex instanceof StopIteration replaced with ex === StopIteration.

var obj = {a:1,b:2,c:3,d:4,e:5,f:6},
   iter = new Iterator(obj, true);

while (true) {
    try {
        doSomethingWithProperty(iter.next());
    } catch (ex if (ex instanceof StopIteration)) {
        break;
    }
}