.decrementExact()

The Math.decrementExact() method returns the argument decremented by one. It throws an exception if the result overflows the specified data type of the argument.

Math.decrementExact(num)

The num parameter is of type long or int.

The following example uses the .decrementExact() method to decrement the input by 1:

// Main.java
public class Main {
  public static void main(String[] args) {
    int value = 21;
    long input = 123L;
    long negValue = -38L;
    System.out.println(Math.decrementExact(value));
    System.out.println(Math.decrementExact(input));
    System.out.println(Math.decrementExact(negValue));
  }
}

This will produce the following output:

20
122
-39