Do Power in Java

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Mohammad Irfan Jan 25, 2021 Dec 09, 2020
Java Java Math
  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
Do Power 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 our 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

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