A quick programming guide to calculate the power of a number without using Math.pow() method. Example, find power of number using for and while loop.
1. Overview
In this tutorial, you are going to learn how to find the power of a number without using Math.pow() method.
But, the power of a number can be solved with the help of for loop and while loops.
Example:
Input: Base = 4, Exponent : 3
Output: 63
Finding the power is to multiply the base with exponent value that means here base is 4 and exponent is 3.
So, power calculation is 4 * 4 * 4 = 64.
2. Example 1 - Power Of A Number Using For Loop
In the below program, first created two integer type variables base and exponent.
Next, run through the for loop for exponent times and multiply the base value those many times.
public class NumberPowerForLoopExample {
public static void main(String[] args) {
// create two variables to store the base and exponenet values
int base = 4;
int exponent = 3;
// printing the input values
System.out.println("Base : " + base + ", Exponent : " + exponent);
// a result variable to store the output
int result = 1;
// Calculating the power using for loop
for (int i = 1; i <= exponent; i++) {
result = result * base;
}
// Printing the output
System.out.println("Result : " + result);
}
}
Output:
Base : 4, Exponent : 3 Result : 64
3. Example 2 - Power Of A Number Using While Loop
Next, run the same logic using while loop until the exponent is 0.
Look at the below example and output.
public class NumberPowerWhileLoopExample {
public static void main(String[] args) {
// create two variables to store the base and exponenet values
int base = 5;
int exponent = 4;
// printing the input values
System.out.println("Base : " + base + ", Exponent : " + exponent);
// a result variable to store the output
int result = 1;
// Calculating the power using while loop
while (exponent > 0) {
result = result * base;
exponent--;
}
// Printing the output
System.out.println("Result : " + result);
}
}
Output:
Base : 5, Exponent : 4 Result : 625
4. Example 3 - Power Of A Number Using Math.pow() Method
In the last approach, you can use the java Math API builtin method pow(base, exponent) which does the calculation of power of a given number for the given exponent.
This can be done using recursive approach
package com.javaprogramto.programs.numbers;
public class NumberPowerMathPowExample {
public static void main(String[] args) {
// create two variables to store the base and exponenet values
int base = 5;
int exponent = 7;
// printing the input values
System.out.println("Base : " + base + ", Exponent : " + exponent);
// a result variable to store the output
double result = 1;
// Calculating the power using Math.pow() method
result = Math.pow(base, exponent);
// Printing the output
System.out.println("Result : " + result);
}
}
Output:
Base : 5, Exponent : 7
Result : 78125.0
5. Conclusion
In this article, you've seen the three ways to find the power of a number.
All examples are over GitHub.
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