In this program, you'll learn to calculate the power of a number with and without using pow() function.
Example 1: Calculate power of a number using a while loop
Calculate the Power of a Number
public class Power {
public static void main(String[] args) {
int base = 3, exponent = 4;
long result = 1;
while (exponent != 0)
{
result *= base;
--exponent;
}
System.out.println("Answer = " + result);
}
}
When you run the program, the output will be:
Answer = 81
In this program, base and exponent are assigned values 3 and 4 respectively.
Using the while loop, we keep on multiplying result by base until exponent becomes zero.
In this case, we multiply result by base 4 times in total, so result = 1 * 3 * 3 * 3 * 3 = 81.
Example 2: Calculate power of a number using a for loop
public class Power {
public static void main(String[] args) {
int base = 3, exponent = 4;
long result = 1;
for (;exponent != 0; --exponent)
{
result *= base;
}
System.out.println("Answer = " + result);
}
}
When you run the program, the output will be:
Answer = 81
Here, instead of using a while loop, we've used a for loop.
After each iteration, exponent is decremented by 1, and result is multiplied by base exponent number of times.
Both programs above doesn't work if you have a negative exponent. For that, you need to use pow() function in Java standard library.
Example 3: Calculate the power of a number using pow() function
public class Power {
public static void main(String[] args) {
int base = 3, exponent = -4;
double result = Math.pow(base, exponent);
System.out.println("Answer = " + result);
}
}
When you run the program, the output will be:
Answer = 0.012345679012345678
In this program, we use Java's Math.pow() function to calculate the power of the given base.
