Why do people still use primitive types in Java?

Question

Since Java 5, we\'ve had boxing/unboxing of primitive types so that int is wrapped to be java.lang.Integer, and so and and so forth.

I see

Answer 1

Couple of reasons not to get rid of primitives:

• Backwards compatability.

If it's eliminated, any old programs wouldn't even run.

• JVM rewrite.

The entire JVM would have to be rewritten to support this new thing.

• Larger memory footprint.

You'd need to store the value and the reference, which uses more memory. If you have a huge array of bytes, using byte's is significantly smaller than using Byte's.

• Null pointer issues.

Declaring int i then doing stuff with i would result in no issues, but declaring Integer i and then doing the same would result in an NPE.

• Equality issues.

Consider this code:

Integer i1 = 5;
Integer i2 = 5;

i1 == i2; // Currently would be false.

Would be false. Operators would have to be overloaded, and that would result in a major rewrite of stuff.

• Slow

Object wrappers are significantly slower than their primitive counterparts.