Golang : Check if integer is power of four example

Problem:

You need to test if a given integer is a power of 4. For example, if given number = 16, return true and if number = 9 return false.

Solution:

Test to see if the number can be divided by 4 until it is 1.

 package main

 import (
 "fmt"
 "math"
 )

 func isPowerOfFour(num int) bool {
 for num >= 4 {
 if num%4 != 0 {
 return false
 }
 num = num / 4
 }
 return num == 1
 }

 func main() {

 fmt.Println("Is 9 power of 4? : ", isPowerOfFour(9))

 fmt.Println("Is 64 power of 4? : ", isPowerOfFour(64))

 fmt.Println("Is 8 power of 4? : ", isPowerOfFour(8))

 // if use math.Pow() function, remember to convert float64
 // to int
 testNumPowerOfFour := int(math.Pow(2, 4))
 fmt.Println("Is 16 power of 4? : ", isPowerOfFour(testNumPowerOfFour))

 testNumPowerOfFour = int(math.Pow(2, 3))
 fmt.Println("Is 8 power of 4? : ", isPowerOfFour(testNumPowerOfFour))
 }

Output:

Is 9 power of 4? : false

Is 64 power of 4? : true

Is 8 power of 4? : false

Is 16 power of 4? : true

Is 8 power of 4? : false

References:

https://www.socketloop.com/tutorials/golang-math-pow-the-power-of-x-y-example