finding sum of prime numbers under 250

Question

var sum = 0

for (i = 0; i < 250; i++) {

    function checkIfPrime() {

        for (factor = 2; factor < i; factor++) {
            if (i % factor = 0) {
            


        

Answer 1

Here is a simple way of looping through array and implementing the sieve of Eratosthenes...

function sumPrimes(num) {
  var t, v = [],
    w = [],
    x = [],
    y = [],
    z = 0;
  //enumerating Vee array starts at 2 as first prime number
  for (let a = 2; a <= num; a++) {
    v.push(a)
  }
  //creating a moving loop by splicing its first index
  for (let i = 0; i < v.length; i) { //ensure all items spliced 
    t = v[i]; // t as prime to be removed from Vee array 
    x.push(t); // x storage of primes
    z += t //  total of peculiar primes
    w.push(v.splice(i, 1)) //tested to move all one by one
    // prompt(v) //tested that v loses its v[i] every iteration
    //= now trying to remove others using remainder (%) vs prime t
    for (let vi in v) {
      v[vi] % t === 0 ? y.push(v.splice(vi, 1)) : ""; //recursive removal of composite items by prime t
    }
  }
  return z // returns sum of primes
}
sumPrimes(250);

You generate the array beginning with 2 as first prime, You sieve the array removing items by the remainder of prime using % === 0. The you loop through the remaining array by using the next prime until the last remaining prime is pushed to the prime arrays. Add all primes to get the Sum.

Answer 2

As per the "Sieve of Eratosthenes", I have implemented the code using JS:

function isPrime(n){
  return ((n/2 === 1 || n/3 === 1 || n/5 === 1 || n/7 === 1)?true:(n%2===0 || n%3 === 0 || n%5 ===0 || n%7 === 0)?false:true);
};

var val = 250;

let outArr = [];
for(let i=2;i<val;i++){
  if(isPrime(i)){
    outArr.push(i);
  }  
}
console.log("Prime number between 0 - "+val+" : "+outArr.join(","));