Question

In my code there are a lot of final values, like 10000. They never change, i do nothing with them, just sometimes checks like if(number1 == number2).

Is it better to use int or Integer for such numbers?

Answer 1

In your case, use int.

In a general case, if you’re in the situation where you could feasibly use either the primitive value is almost always preferred:

• They’re potentially more memory efficient
• You can always use == reliably, which isn’t the case with the class Integer type – you’d have to use .equals() to ensure you were getting what you wanted. See here for more details.

Memory requirements are a lot less of an issue these days, but the big gotcha is the second one, which can cause the potential for a lot of bugs if you’re not aware of it (especially since there’s cases where == will work as you expect, and others where it won’t – it’s not a “reliable” bug in that sense.)