Java Math nextDown() Method

The nextDown() method of Math class returns the floating-point number adjacent to the argument in direction of the negative infinity.

Syntax:

1. public static double nextDown (double d)
2. public static float nextDown (float f)

Parameters:

The parameters ‘d’ and ‘f’ represent the starting floating-point values.

Return Value:

The nextDown () method returns the floating-point number which is closer to negative infinity.

Special cases of the nextDown() method are as follows:

• It returns NaN, is the argument passed is NaN.
• It returns negative infinity, if the argument is negative infinity.
• It returns –Double.MIN_VALUE, is the argument is zero.

Example 1:

public class JavaMathNextDownExample1 {
    public static void main(String[] args) {
        float f = 123.78f;
        // returns the floating-point number which is closer to negative infinity
        System.out.println("Floating-point number : "+Math.nextDown(f));
    }
}

Output:

Floating-point number : 123.77999

Example 2:

public class JavaMathNextDownExample2 {
    public static void main(String[] args) {
        Double d = -0d;
        // returns the floating-point number which is closer to negative infinity
        System.out.println("Floating-point number : "+Math.nextDown(d));
    }
}

Output:

Floating-point number : -4.9E-324

Example 3:

public class JavaMathNextDownExample3 {
    public static void main(String[] args) {
        Double d = Double.NaN;
        //returns NaN, is the argument passed is NaN.
        System.out.println("Floating-point number : "+Math.nextDown(d));
    }
}

Output:

Floating-point number : NaN

Example 4:

public class JavaMathNextDownExample4 {
    public static void main(String[] args) {
        Double d = Double.NEGATIVE_INFINITY;
        // returns negative infinity, if the argument is negative infinity
        System.out.println("Floating-point number : "+Math.nextDown(d));
    }
}

Output:

Floating-point number : -Infinity

Example 5:

public class JavaMathNextDownExample5 {
    public static void main(String[] args) {
        Double d = 0.0d;
        //returns –Double.MIN_VALUE, is the argument is zero.
        System.out.println("Floating-point number : "+Math.nextDown(d));
    }
}

Output:

Floating-point number : -4.9E-324