Java Program - Power of a Number


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If power (or exponential) of number indicates how many the number is multiplied by itself to get the final number. For example:

$$x$$ raised to the power $$2$$ = $$x^2 = x*x$$

$$x$$ raised to the power $$3$$ = $$x^3 = x*x*x$$

Example: Using conditional statement

In the below example, a method called Power() is created to calculate power of a number. It uses while loop to achieve this. This method can be used to calculate the power of a number where power should be a non-negative integer.

public class MyClass {
  static void Power(double x, int n) {
    double finalnum = 1;
    int n1 = n;
    while(n1 > 0){
      finalnum = finalnum * x;
      n1--;
    }
    System.out.println(x + " raised to the power " + n + " = " + finalnum);
  }

  public static void main(String[] args) {
    Power(3, 5);
    Power(5, 0);
    Power(6, 2);
  }
}

Output

3.0 raised to the power 5 = 243.0
5.0 raised to the power 0 = 1.0
6.0 raised to the power 2 = 36.0

Example: Using pow() method of Java Math Class

The pow() method of Java Math class can also be used to calculate power of a number. It can be used to calculate $$x^n$$ for any value of n (n can be negative or fraction).

import java.lang.Math;

public class MyClass {
  public static void main(String[] args) {
    double x = 3, y = 5, z = 6;
    double a = 5, b = 0, c = 2;

    System.out.println(x + " raised to the power " + a + " = " + Math.pow(x, a));
    System.out.println(y + " raised to the power " + b + " = " + Math.pow(y, b));
    System.out.println(z + " raised to the power " + c + " = " + Math.pow(z, c));
  }
}

Output

3.0 raised to the power 5.0 = 243.0
5.0 raised to the power 0.0 = 1.0
6.0 raised to the power 2.0 = 36.0

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