How do I round a number?

The example below show you some methods of the Math class that can be use to round the value of a number. These methods are Math.ceil(), Math.floor() and Math.round().

package org.kodejava.example.math;

public class GetRoundingValueExample {

    public static void main(String[] args) {
        Double number = 1.5D;

        //
        // Get the smallest value that is greater than or equal to the
        // argument and is equal to a mathematical integer
        //
        double roundUp = Math.ceil(number);
        System.out.println("Result of rounding up of " + number + " = " + roundUp);

        //
        // Get the largest value that is less than or equal to the
        // argument and is equal to a mathematical integer
        //
        double roundDown = Math.floor(number);
        System.out.println("Result of rounding down of " + number + " = " + roundDown);

        //
        // Get the closest long value to the argument
        //
        long round1 = Math.round(number);
        System.out.println("Rounding result of " + number + " (in long) =  " + round1);

        //
        // Get the closest int value to the argument
        //
        int round2 = Math.round(number.floatValue());
        System.out.println("Rounding result of " + number + " (in int) = " + round2);
    }
}

Here are the result of the program:

Result of rounding up of 1.5 = 2.0
Result of rounding down of 1.5 = 1.0
Rounding result of 1.5 (in long) =  2
Rounding result of 1.5 (in int) = 2
Wayan Saryada

Wayan Saryada

A programmer, runner, recreational diver, currently living in the island of Bali, Indonesia. Mostly programming in Java, creating web based application with Spring Framework, JPA, etc. If you need help on Java programming you can hire me on Fiverr.
Wayan Saryada

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