Java floor() method with Examples

The Math.floor() method in Java returns the largest integer value that is less than or equal to a given number. The result is returned as a double and represents the mathematical floor of the argument. This method is part of the java.lang.Math class.

class GFG {
    public static void main(String[] args) {
        double num = 2.7;
        System.out.println(Math.floor(num));
    }
}

2.0

Explanation:

• A decimal value 2.7 is stored in the variable num.
• Math.floor(num) rounds the value downward to the nearest integer.
• The result is returned as a double (2.0).

Syntax

public static double floor(double a)

• Parameter: "a" the double value whose floor is to be determined.
• Return Value: Returns the nearest integer value (as double) that is less than or equal to the given argument.

Special Cases

• If the argument is already an integer, the same value is returned.
• If the argument is NaN, positive infinity, negative infinity, positive zero, or negative zero, the result is the same as the argument.
• Negative numbers between -1.0 and 0.0 are floored to -1.0.

Example 1: This program demonstrates how the Math.floor() method rounds different types of double values down to the nearest integer in Java.

import java.lang.Math;
class GFG {
    public static void main(String args[]) {
        double a = 4.3;
        double b = 1.0 / 0;
        double c = 0.0;
        double d = -0.0;
        double e = -2.3;
        System.out.println(Math.floor(a)); 
        System.out.println(Math.floor(b)); 
        System.out.println(Math.floor(c)); 
        System.out.println(Math.floor(d)); 
        System.out.println(Math.floor(e)); 
    }
}

4.0
Infinity
0.0
-0.0
-3.0

Explanation:

• The Math class is used to access the floor() method.
• Variable a = 4.3 is a positive decimal; Math.floor(a) rounds it down to 4.0.
• Variable b = 1.0 / 0 represents positive infinity, and Math.floor(b) returns Infinity.
• Variable c = 0.0 is positive zero, and the output remains 0.0.
• Variable d = -0.0 is negative zero, and the output remains -0.0.
• Variable e = -2.3 is a negative decimal; Math.floor(e) rounds it down to -3.0.
• Each result is printed to demonstrate how Math.floor() behaves for different input values.

Example 2: This program shows how the Math.floor() method rounds a positive decimal number down to the nearest integer in Java.

class GFG {
    public static void main(String[] args) {
        double number = 3.5;
        double result = Math.floor(number);
        System.out.println(result);
    }
}

Output : 

3.0

Explanation:

• A decimal value 3.5 is stored in the variable number.
• The Math.floor(number) method rounds the value downward to the nearest integer.
• The result is returned as a double (3.0).

Related Articles

• Java Math Class
• Java ceil() Method
• Java round() Method
• Difference between ceil() and floor()