Java Math round()

The Java Math round() method rounds the specified value to the closest int or long value and returns it.

That is, 1.2 is rounded to 1 and 1.8 is rounded to 2.

The syntax of the round() method is:

Math.round(value)

Here, round() is a static method. Hence, we are accessing the method using the class name, Math.


round() Parameters

The round() method takes a single parameter.

  • value - number which is to be rounded

Note: The data type of the value should be either float or double.


round() Return Value

  • returns the int value if the argument is float
  • returns the long value if the argument is double

The round() method:

  • rounds upward if the value after the decimal is greater than or equal to 5
    1.5 => 2
    1.7 => 2
    
  • rounds downward if the value after the decimal is smaller than 5
    1.3 => 1

Example 1: Java Math.round() with double

class Main {
  public static void main(String[] args) {

    // Math.round() method
    // value greater than 5 after decimal
    double a = 1.878;
    System.out.println(Math.round(a));  // 2

    // value equals to 5 after decimal
    double b = 1.5;
    System.out.println(Math.round(b));  // 2

    // value less than 5 after decimal
    double c = 1.34;
    System.out.println(Math.round(c));  // 1
  }
}

Example 2: Java Math.round() with float

class Main {
  public static void main(String[] args) {

    // Math.round() method
    // value greater than 5 after decimal
    float a = 3.78f;
    System.out.println(Math.round(a));  // 4

    // value equals to 5 after decimal
    float b = 3.5f;
    System.out.println(Math.round(b));  // 4

    // value less than 5 after decimal
    float c = 3.44f;
    System.out.println(Math.round(c));  // 3
  }
}

Recommended Tutorials