Integer value comparison

Question

I\'m a newbie Java coder and I just read a variable of an integer class can be described three different ways in the API. I have the following code:

if (count.         


        

Answer 1

It's better to avoid unnecessary autoboxing for 2 reasons.

For one thing, it's a bit slower than int < int, as you're (sometimes) creating an extra object;

void doSomethingWith(Integer integerObject){ ...
  int i = 1000;
  doSomethingWith(i);//gets compiled into doSomethingWith(Integer.valueOf(i));

The bigger issue is that hidden autoboxing can hide exceptions:

void doSomethingWith (Integer count){
  if (count>0)  // gets compiled into count.intValue()>0

Calling this method with null will throw a NullPointerException.

The split between primitives and wrapper objects in java was always described as a kludge for speed. Autoboxing almost hides this, but not quite - it's cleaner just to keep track of the type. So if you've got an Integer object, you can just call compare() or intValue(), and if you've got the primitive just check the value directly.