Question

I read Is there a performance difference between i++ and ++i in C?:

Is there a performance difference between i++ and ++i if the resulting value is not used?

What’s the answer for JavaScript?

For example, which of the following is better?

1. for (var i = 0; i < max; i++) {
     // code
   }
   

2. for (var i = 0; i < max; ++i) {
     // code
   }
   

Answer 1

Here is an article about this topic: http://jsperf.com/i-vs-i/2

++i seems to be slightly faster (I tested it on firefox) and one reason, according to the article, is:

with i++, before you can increment i under the hood a new copy of i must be created. Using ++i you don’t need that extra copy. i++ will return the current value before incrementing i. ++i returns the incremented version i.