JSFiddle - React, Tailwind, and code Playground

JavaScript

function PrimeMover(num) {
    var prime = [];
    //find la list of the prime numbers
    for (var i = 0; i < 10000; i++) {
        if (i < 2 || i != Math.round(i)) {
            continue;
        }
        var isPrime = true
        for (var j = 2; j <= Math.sqrt(i); j++) {
            if (i % j == 0) {
                isPrime = false;
                continue;
            }
        }
        if(isPrime){
            prime.push(i);
        }
    }
    return prime;
    //according to the index given, return the value
    for (var i = 0; i < prime.length; i++) {
        if (num - 1 === i) {
            return prime[i];
        }
    }
}

//function isPrime(num) {
//    if (num < 2 || num != Math.round(num)) {
//        return false;
//    }
//    for (var i = 2; i <= Math.sqrt(num); i++) {
//        if (num % i == 0) {
//            return false;
//        }
//    }
//    return true;
//}
console.log(PrimeMover(100));
//console.log(PrimeMover(9));
//console.log(PrimeMover(20));