# Kotlin Program to Calculate the Power of a Number

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 without using pow()

``````fun main(args: Array<String>) {
val base = 3
var exponent = 4
var result: Long = 1

while (exponent != 0) {
result *= base.toLong()
--exponent
}

}``````

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. We also need to cast base to `Long` because result only accepts `Long` and Kotlin focuses on type safety.

However, as in Java, above code doesn't work if you have a negative exponent. For that, you need to use pow() function in Kotlin

Here's the equivalent Java code: Java Program to calculate power of a number

## Example 2: Calculate power of a number using pow()

``````fun main(args: Array<String>) {
val base = 3
val exponent = -4
val result = Math.pow(base.toDouble(), exponent.toDouble())

`Answer = 0.012345679012345678`
We also need to convert base and exponent to `Double` because, pow only accepts `Double` parameters.