The NumericConvert program shows some of the potential problems that you may encounter as the result of numeric promotion. As is, the program compiles, runs, and displays a value of 11 as its output. However, if you remove the parentheses from around (b + 1) or remove the (byte) cast operator, the program will not compile. That is because in the expression (b + 1), b is promoted to an int and added to 1.
The result of the expression is an int value. This value must be explicitly cast to a byte in order to avoid the compilation error.

public class NumericConvert {
  public static void main(String[] args) {
    byte b = 10;
    b = (byte)(b + 1);
    System.out.println(b);
  }
}