# Java source code in Recursive function for X to the power Y

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Recursive Power Program

Below is a java source code for the recursive function of x to the power y. This program again is dealing with recursion, it just prompt the user to enter the base number and base power and the program will solve the correct answer. If the power of the base is zero it simply return 1, if the power is 1 the program will return the value of x, if it greater than one it just multiply the base number many times as the power indicated, and if the power is negative, the program simply multiply the power into -1, get the answer of the x raise to power y and finally divided it on 1. To understand the formula more, below is the recursive definition of the program.

Recursive Definition:

```		{1                 if y=0
power(x, y) =   {x  		   if y=1
{x + power(x, y-1) if y>1

1
if y<0, power(x, y) =     _____________
power(x, -y)```

Java source code: Recursive function for X to the power Y

```// java class

public class Power
{
public static double power(double base, double basePow)
{

if(basePow==0)
{
return 1;
}
else if(basePow==1)
{
return base;
}
else if(basePow>1)
{
return base*power(base,basePow-1);
}
else
{

return 1/power(base, -1 * basePow);
}

}

}

//main class

import java.util.Scanner;

public class Main {

public static void main(String[] args)
{
Scanner input = new Scanner(System.in);

System.out.print("Enter the base number: ");
double base = input.nextInt();

System.out.print("Enter the base power: ");
double basePow = input.nextInt();

Power access = new Power();

System.out.print(base + " to the power of " + basePow + " is: " + access.power(base, basePow));

}

}

```

Below is the sample output of the program.

Sample Output 1:

Enter the base number: 10

Enter the base power: 0

10.0 to the power 0.0 is: 1

Sample Output 2:

Enter the base number: 2

Enter the base power: 10

2.0 to the power of 10.0 is: 1024.0

Sample Output 3:

Enter the base number: 5

Enter the base power: -2

5.0 to the power of -2.0 is: 0.04

working