Java Math round()

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

    double a = 3.87;
    System.out.println(Math.round(a));

  }
}

// Output: 4

Syntax of Math.round()

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

  }
}

Also Read:

• Java Math.floor()
• Java Math.ceil()