In this java program, we will learn about how to calculate the power of a number using loops, using Math.pow() method and using recursion.

To calculate the power of a number(A^{N}) we repetitively multiply base number(A) to inself up to exponent(N) times.

For Example

A^{N}= A*A*A*A..... N times A^{5}= A*A*A*A*A

To understand this java program, you should have understanding of the following Java programming concepts:

## Java Program to calculate power of a number using a loop

public class PowerOfNumberLoop { public static void main(String[] args) { int base = 2, exponent = 6, result = 1; for( int i = 1; i <= exponent ; i++) { result = result * base; } System.out.println("2^6 = " +result); } }Output

2^6 = 64

Using the for loop, we multiplying the result by base up to exponent times.

## Java Program to calculate power of a number using recursion

public class PowerOfNumberRecursion { // Function to calculate A^N static int power(int base, int exponent) { if (exponent == 0) return 1; else return base * power(base, exponent-1); } public static void main(String[] args) { System.out.println("2^6 = " + power(2, 6)); } }Output

2^6 = 64

In above java program, we are using following recurrence relation to calculate A^{N}.

ALet power(A, N) is a function to calculate A^{N}= A*A*A*A..... N times A^{N}= A * A^{N-1}

^{N}. As per the above recurrence equation, To find power(A, N) we can first calculate power(A, N-1) then multiply it with A. power(A, N) = A * power(A, N-1)

## Java Program to calculate power of a number using Math.pow() method

public class PowerOfNumberPowMethod { public static void main(String[] args) { int base = 2, exponent = 6; double result = Math.pow(base, exponent); System.out.println("2^6 = " +result); } }Output

2^6 = 64.0

In this program, we use Java's Math.pow() function to calculate the power of a number.