.multiplyExact()

The .multiplyExact() method returns the product of its arguments.

Syntax

Math.multiplyExact(x, y)

The .multiplyExact() method takes two parameters: x and y (a multiplicand and multiplier). Both parameters must be of either type int or long.

The .multiplyExact() method returns the result of x multiplied by y.

An exception is thrown if the result exceeds type int or long or is equal to:

  • Integer.MAX_VALUE
  • Integer.MIN_VALUE
  • Long.MAX_VALUE
  • Long.MIN_VALUE

Example

In the following example, the .multiplyExact() method first returns the product of two numbers and then throws an exception:

// Main.java
public class Main {
public static void main(String[] args) {
int num1 = 8;
int num2 = 2;
/*
Returns the product of the two numbers
*/
System.out.println(num1 + " multiplied by " + num2 + " equals to " + Math.multiplyExact(num1, num2));
long c = 299792458;
long m = Long.MAX_VALUE;
/*
Overflow will occur if any one of the arguments is
Long.MAX_VALUE or Integer.MAX_VALUE.
*/
System.out.println(Math.multiplyExact(c, m));
}
}

This will produce the following output:

8 multiplied by 2 equals to 16
Exception in thread "main" java.lang.ArithmeticException: long overflow
at java.base/java.lang.Math.multiplyExact(Math.java:946)
at Main.main(Main.java:17)

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