Long vs Integer, long vs int, what to use and when?

Question

Sometimes I see API\'s using long or Long or int or Integer, and I can\'t figure how the decision is made for that?

Answer 1

There are a couple of things you can't do with a primitive type:

• Have a null value
• synchronize on them
• Use them as type parameter for a generic class, and related to that:
• Pass them to an API that works with Objects

Unless you need any of those, you should prefer primitive types, since they require less memory.