Why I can't perform mathematical operations using short variable?

Question

short s1 = 4500, s2 = 9800;
short s3;
s3 = s2 - s1;
System.out.println("The difference is:- " + s3);

I ran this code and it is showing an error but work perfectly when I declare s3 as int. Why is this happening? The error it is showing is as follows :- ''' Main.java:15: error: incompatible types: possible lossy conversion from int to short s3 = s2 - s1; ^ 1 error '''

I tried running the code and I thought the code would run. But in mathematical operations it shows error and suggests that instead of short, byte variable use int variable.

Answer 1

In Java, when you perform arithmetic operations on primitive data types, like shorts in this case, the resulting value is automatically promoted to at least an int before the operation is performed. This is known as "integer promotion." This is done to prevent potential loss of data or precision that might occur if the operation was performed directly with smaller data types like shorts or bytes.

Try this:

    short s1 = 3, s2 = 4;
    short s3;
    s3 = (short)(s2 - s1);

By adding (short) before the subtraction, you are telling Java to perform the subtraction as an int, and then explicitly cast the result back to a short. Just be aware that if the result of the subtraction is outside the range of a short, you may lose data or encounter unexpected behavior.