JS is judged whether the number is a prime number

<script>

@ Primes: 1 and itself in addition, no other number is called the number of divisible it can be such a prime number

// define a random number

var num = + prompt ( "Please enter a positive integer greater than 2");

// define a variable mark this tag variables can be responsible if there is divisible by the number of marks in circulation

var ISZ = true;

for ( var i = 2; i <Num; i ++) {

if (num % i === 0) {

// Description from between 2-10 can be several then it is not a prime number divisible by 11

ISZ = false;

}

}

// If true judgment isZ explanation cycle if statement did not enter it means that there is no number divisible by 11

if (isZ) {

alert (num + "is a prime number");

} else {

alert (num + "is not a prime number");

}

</script>