JavaScript for…in vs for

Question

Do you think there is a big difference in for...in and for loops? What kind of \"for\" do you prefer to use and why?

Let\'s say we have an array of associative array

Answer 1

FYI - jQuery Users

---

jQuery's each(callback) method uses for( ; ; ) loop by default, and will use for( in ) only if the length is undefined.

Therefore, I would say it is safe to assume the correct order when using this function.

Example:

$(['a','b','c']).each(function() {
    alert(this);
});
//Outputs "a" then "b" then "c"

The downside of using this is that if you're doing some non UI logic, your functions will be less portable to other frameworks. The each() function is probably best reserved for use with jQuery selectors and for( ; ; ) might be advisable otherwise.

---