In this post Java Program to Calculate the Power of a Number you will learn how to find the power of a number with and without using pow() function.
Approach 1:
Here, either we can use while loop or for loop. We have core logic is that after each iteration exponent is decremented by 1 and result is multiplied by base exponent number of times.
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package com.kkjavatutorials.clients; import java.util.Scanner; /** * @author KK JavaTutorials *This java Program is all about How to Calculate the Power of a Number */ public class CalculatePowerOfNumberTest1 { public static void main(String[] args) { Scanner scanner = null; try { //Take base and exponent number from keyboard using Scanner scanner = new Scanner(System.in); System.out.println("Enter base Number:"); //Take either zero,positive or negative base number int base = scanner.nextInt(); //Take either zero or positive exponent number System.out.println("Enter exponent Number:"); int exponent = scanner.nextInt(); int exp =exponent; long result = 1; for (;exponent != 0; --exponent){ result *= base; } System.out.println(base+" to power "+exp+" is:" + result); } catch (Exception e) { e.printStackTrace(); }finally { if(scanner != null) scanner.close(); } } } |
I have tested above programs for few inputs as below. You may test for other input as well
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Enter base Number: 5 Enter exponent Number: 3 5 to power 3 is:125 ------------------------------------------------------------------------------------------------- Enter base Number: -4 Enter exponent Number: 3 -4 to power 3 is:-64 ------------------------------------------------------------------------------------------------- Enter base Number: 0 Enter exponent Number: 2 0 to power 2 is:0 ------------------------------------------------------------------------------------------------- Enter base Number: 10 Enter exponent Number: 0 10 to power 0 is:1 |
Approach 2:
What we have seen above Approach 1 that will not work if you have a negative exponent. For that, you may to use pow() function in Java standard library.
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package com.kkjavatutorials.clients; import java.util.Scanner; /** * @author KK JavaTutorials *This Java Program is all about How to Calculate the Power of a Number using pow() * function in Java standard library. */ public class CalculatePowerOfNumberTest2 { public static void main(String[] args) { Scanner scanner = null; try { //Take base and exponent number from keyboard using Scanner scanner = new Scanner(System.in); System.out.println("Enter base Number:"); //Take either zero,positive or negative base number int base = scanner.nextInt(); //Take either zero,positive or negative exponent number System.out.println("Enter exponent Number:"); int exponent = scanner.nextInt(); double result = Math.pow(base, exponent); System.out.println(base+" to power "+exponent+" is:" + result); } catch (Exception e) { e.printStackTrace(); }finally { if(scanner != null) scanner.close(); } } } |
I have tested above programs for few inputs as below. You may test for other input as well
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Enter base Number: 2 Enter exponent Number: -3 2 to power -3 is:0.125 --------------------------------------------------------------------------- Enter base Number: 20 Enter exponent Number: 3 20 to power 3 is:8000.0 -------------------------------------------------------------------------- Enter base Number: -6 Enter exponent Number: 3 -6 to power 3 is:-216.0 |
That’s all in this post of Java Program to Calculate the Power of a Number
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