IsPrime

func isPrime(num: Number): Boolean {    for (var i = 2; i < num; i += 1) {        if (num % i == 0) return false    }    return true}
print(isPrime(17)) # trueprint(isPrime(97)) # trueprint(isPrime(18)) # falseprint(isPrime(54)) # false

This function checks if a number is prime by looping through all the factors needed for it to be composite.