Question

Can someone explain to me the usage of Integer, Boolean etc in place of their primitive types in JAVA?

I can’t seem to grasp the advantages their are providing. They seem to create unnecessary problems of handling null values.

Thanks!

Answer 1

Boolean, Integer, Long, … are Objects. You can use them in places where you can’t use primitive types, e.g.

• storing them in a Collection like a Map
• using them as template parameter
• assigning them a null value
• using them in a more general way (e.g. Long as Number)

Examples:

new ArrayList<Integer>();
Long id = null;
Number num = new Long( 3 );