Does using Integer in loop makes any difference?

Question

I've been using int in for-loop. Like below:

for (int i = 0; i < 100 ; i++) {
     //Do something...
}

If I use Integer instead of int, like below, does it makes any difference?

for (Integer i = 0; i < 100 ; i++) {
     //Do something...
}

Answer 1

Yes, it will require auto-unboxing and auto-boxing for each iteration. It'll work the same way, and you don't need to do anything to make it work, but it's unnecessary and easily avoided.

Also it might slightly slow down the loop for no real advantage.

Basically Integer should only ever be used when you actually need the number to be an Object (for example when you put it into a collection, when null is a valid value, ...). At all other times, you should use the primitive types where possible (int, char, ...).