Do Power in Java

  1. Raise a Number to a Power Using the pow() Method in Java
  2. Raise a Number to Power Using the while Loop in Java
  3. Raise a Number to Power Using the for Loop in Java
  4. Raise a Number to a Power Using the recursion in Java

This tutorial introduces how to do power operation in Java and lists some example codes to understand the topic.

To raise a number to a power in Java, we can use the pow() method of the Math class or own custom code that uses loop or recursion technique. Let’s see some examples.

Raise a Number to a Power Using the pow() Method in Java

The pow() method belongs to the Math class in Java used to generate a number of the given power. It is a simple and straightforward approach because pow() is a built-in method that reduces the effort to write custom code. See the example below.

public class SimpleTesting{
    public static void main(String[] args) {
        double a = 20;
        double power = 2;
        double result = Math.pow(a, power);
        System.out.println(a+" power of "+power + " = "+result);
    }
}

Output:

20.0 power of 2.0 = 400.0

Raise a Number to Power Using the while Loop in Java

If you don’t want to use the built-in pow() method, then use the custom code below. We use a while loop inside this code to generate a number to a power. See the example below.

public class SimpleTesting{
    public static void main(String[] args) {
        double a = 20;
        double power = 2;
        double result = 1;
        double temp = power;

        while (temp != 0)
        {
            result *= a;
            --temp;
        }
        System.out.println(a+" power of "+power + " = "+result);
    }
}

Output:

20.0 power of 2.0 = 400.0

Raise a Number to Power Using the for Loop in Java

If you don’t want to use the built-in pow() method, use the custom code below. We use the for loop inside this code to generate a number to a power. See the example below.

public class SimpleTesting{
    public static void main(String[] args) {
        double a = 20;
        double power = 2;
        double result = 1;
        double temp = power;

        for (;temp != 0; --temp)
        {
            result *= a;
        }
        System.out.println(a+" power of "+power + " = "+result);
    }
}

Output:

20.0 power of 2.0 = 400.0

Raise a Number to a Power Using the recursion in Java

This is another approach where we can use recursion to raise a number to a power in Java. Recursion is a technique in which a function calls itself repeatedly until the base condition meets. Here, we create a recursion method, pow(). See the example below.

public class SimpleTesting{
    static double result = 1;
    static void  pow(double n,double p)
    {
        if(p<=0)
        {
            return;
        }
        else if(n==0 && p>=1)
        { 
            result=0;
            return;
        }
        else
            result=result*n;
        pow(n,p-1);
    }
    public static void main(String[] args) {
        double a = 20;
        double power = 2;
        pow(a,power);
        System.out.println(a+" power of "+power + " = "+result);
    }
    }

Output:

20.0 power of 2.0 = 400.0

Related Article - Java Math

  • Infinity in Java