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

I'd use the different methods based on how I wanted to reference the items.

Use foreach if you just want the current item.

Use for if you need an indexer to do relative comparisons. (I.e. how does this compare to the previous/next item?)

I have never noticed a performance difference. I'd wait until having a performance issue before worrying about it.