Java Math pow() Method

The pow() method of Math class returns the value of first argument raised to the power of second argument i.e. a^b.

Syntax:

public static double pow(double a, double b)

Parameters:

The parameters ‘a’ and ‘b’ represent the base and the exponent.

Return Value:

The pow() method computes the value of a^b.

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

• It returns 1.0, is second argument passed is positive or negative zero.
• It returns the result same as the first argument, if the second argument is 1.0.
• It returns NaN, is either argument is NaN.
• It returns positive infinity, if ‘a’ is greater than 1 and ‘b’ is positive infinity or ‘a’ is less than 1 and ‘b’ is negative infinity.
• It returns positive zero, if ‘a’ is greater than 1 and ‘b’ is negative infinity or ‘a’ is less than 1 and ‘b’ is positive infinity.
• It returns NaN, if absolute value of the first argument is equal to 1 and second argument is infinite.
• It returns positive zero, if ‘a’ is positive zero and ‘b’ is greater than zero or ‘a’ is positive infinity and ‘b’ is less than zero.
• It returns positive infinity, if ‘a’ is positive zero and ‘b’ is less than zero or ‘a’ is positive infinity and ‘b’ is greater than zero.
• It returns positive zero, if ‘a’ is negative zero and ‘b’ is greater than zero but not a finite odd integer or ‘a’ is negative infinity and ‘b’ is less than zero but not a finite odd integer.
• It returns negative zero, if ‘a’ is negative zero and ‘b’ is positive finite odd integer or ‘a’ is negative infinity and ‘b’ is negative finite odd integer.
• It returns positive infinity, if ‘a’ is negative zero and ‘b’ is less than zero but not a finite odd integer or ‘a’ is negative infinity and ‘b’ is greater than zero but not a finite odd integer.
• It returns negative infinity, if ‘a’ is negative zero and ‘b’ is negative finite odd integer or ‘a’ is negative infinity and ‘b’ is positive finite odd integer.
• It returns a^b, if both the arguments are integers.

Example 1:

public class JavaMathPowExample1 {
    public static void main(String[] args) {
        double a = 2;
        double b = 8;
        // computes the value of a raised to the power b
        System.out.println(Math.pow(a,b));
    }
}

Output:

4.0

Example 2:

public class JavaMathPowExample2 {
    public static void main(String[] args) {
        double a = 2;
        double b = -0;
        // returns 1.0, is second argument passed is positive or negative zero.
        System.out.println(Math.pow(a,b));
    }
}

Output:

1.0

Example 3:

public class JavaMathPowExample3 {
    public static void main(String[] args) {
        double a = 2;
        double b = 1;
        // returns the result same as the first argument, if the second argument is 1.0
        System.out.println(Math.pow(a,b));
    }
}

Output:

2.0

Example 4:

public class JavaMathPowExample4 {
    public static void main(String[] args) {
        double a = Double.POSITIVE_INFINITY;
        double b = -1;
        /* returns positive zero, if ‘a’ is positive zero and ‘b’ is greater than zero
        or ‘a’ is positive infinity and ‘b’ is less than zero*/
        System.out.println(Math.pow(a,b));
    }
}

Output:

0.0

Example 5:

public class JavaMathPowExample5 {
    public static void main(String[] args) {
        double a = Double.NEGATIVE_INFINITY;
        double b = -77;
        /* returns negative zero, if ‘a’ is negative zero and ‘b’ is positive finite odd integer or
        ‘a’ is negative infinity and ‘b’ is negative finite odd integer*/
        System.out.println(Math.pow(a,b));
    }
}

Output:

-0.0