Can I pass a primitive type by reference in Java?

Question

I would like to call a method which could potentially take on different versions, i.e. the same method for input parameters that are of type:

• boolean
• byte

Answer 1

The object types of primitive types in Java (Double, Integer, Boolean, etc) are, if I remember correctly, immutable. This means that you cannot change the original value inside a method they are passed into.

There are two solutions to this. One is to make a wrapper type that holds the value. If all you are attempting to do is change the value or get a calculation from the value, you could have the method return the result for you. To take your examples:

public byte getValue(byte theByte) {...}
public short getValue(short theShort) {...}

And you would call them by the following:

Short s = 0;
s = foo.getValue(s);

or something similar. This allows you to mutate or change the value, and return the mutated value, which would allow something like the following:

Short s = foo.getValue(10);

Hope that helps.