Power of a Number in Java

In this section, we will create Java programs to find the power of a number in Java. In order to find the power of a number, multiply the number itself up to exponent times.

Example:

Suppose, 5 is the base and 4 is the exponent. In order to find the power of a number, multiply the number itself 4 times, i.e. (5 * 5 * 5 * 5 = 625).

Power of a Number in Java

Steps to Find Power of a Number

Read or initialize base and exponent.
Take another variable (power) to store the result and initialize it to 1.
Using the for loop or while loop, multiply the base by power and store the result into power.
Repeat the above step (3) until the exponent becomes 0.
Print the result.

Let’s implement the above steps in a Java program.

Java Program to Find the Power of a Number

There are the following ways to find the power of a number:

Using Java for Loop
Using Java while Loop
Using Recursion
Using Java Math.pow() Method

Using for Loop

PowerOfNumberExample1.java

  import java.util.Scanner;  public class PowerOfNumberExample1   {  //function to find the power of a number  static int power(int base, int exponent)  {  int power = 1;  //increment the value of i after each iteration until the condition becomes false  for (int i = 1; i <= exponent; i++)   //calculates power  power = power * base;  //returns power  return power;  }  //driver code  public static void main(String args[])  {  int base, exponent;  Scanner sc=new Scanner(System.in);  System.out.print(“Enter the base: “);  base=sc.nextInt();  System.out.print(“Enter the exponent: “);  exponent=sc.nextInt();  //calling function  int pow=power(base, exponent);  //prints the result  System.out.println(base +” to the power ” +exponent + ” is: “+pow);  }  }  

Output:

Enter the base: 11  Enter the exponent: 3  11 to the power 3 is: 1331

In the above program, we can replace the for loop with the following for loop, the logic is quite different but gives the same result.

  int base = 3, exponent = 4;  long result = 1;  for (; exponent!= 0; –exponent)   {  result = result * base;  }  

Using while Loop

PowerOfNumberExample2.java

  import java.util.Scanner;  public class PowerOfNumberExample2  {  public static void main(String args[])   {  int base, exponent, expo;  Scanner sc=new Scanner(System.in);  System.out.print(“Enter the base: “);  base=sc.nextInt();  System.out.print(“Enter the exponent: “);  exponent=sc.nextInt();  expo=exponent;  long power = 1;  //executes until the condition becomes false  while (exponent != 0)   {  //calculates power      power = power * base;  //decrements the power by 1   –exponent;  }  //prints result  System.out.println(base +” to the power ” +expo + ” is: “+power);  }  }  

Output:

Enter the base: 7  Enter the exponent: 6  7 to the power 6 is: 117649

Using Recursion

PowerOfNumberExample3.java

  import java.util.Scanner;  public class PowerOfNumberExample3  {  //function to find the power of a number  static int power(int b, int e)  {  if (e == 0)  //returns 1 if e (power) of any number is 0  //because a (where a is a number) to the power 0 is always equal to 1  return 1;  else  //calls power function recursively and returns the result  return b * power(b, e – 1);  }  //driver code  public static void main(String args[])  {  int b, e;  Scanner sc=new Scanner(System.in);  System.out.print(“Enter the base: “);  b=sc.nextInt();  System.out.print(“Enter the exponent: “);  e=sc.nextInt();  //prints result  System.out.println(b +” to the power ” +e + ” is: “+power(b, e));  }  }  

Output:

Enter the base: 12  Enter the exponent: 4  12 to the power 4 is: 20736

Using Math.pow() Method

PowerOfNumberExample2.java

  import java.util.Scanner;  public class PowerOfNumberExample4  {  public static void main(String args[])  {  int b, e;  Scanner sc = new Scanner(System.in);  System.out.print(“Enter the base: “);  b = sc.nextInt();  System.out.print(“Enter the exponent: “);  e = sc.nextInt();  //invokes the pow() method of the Math class  double power = Math.pow(b, e);  //prints result  System.out.println(b +” to the power ” +e + ” is: “+power);  }  }  

Output 1:

Enter the base: 2  Enter the exponent: 5  2 to the power 5 is: 32.0

Output 2:

Enter the base: 8  Enter the exponent: -3  8 to the power -3 is: 0.001953125

Output 3:

Enter the base: -10  Enter the exponent: 3  -10 to the power 3 is: -1000.0

Next TopicSum of Prime Numbers in Java

Power of a Number in Java

Power of a Number in Java

Example:

Steps to Find Power of a Number

Java Program to Find the Power of a Number

Using for Loop

Using while Loop

Using Recursion

Using Math.pow() Method

POJO in Java

Sphenic Number in Java

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