Sum All Primes Stuck!

Hi Guys, I am stuck at this challenge for about 2 days and I need help, please. Here is my best code I think


function sumPrimes(num) {
  var prime = [2,3,5,7];
  for (var j = num ; j > 1 ; j-- ){
    var devide2 = j/2;
    var devide3 = j/3 ;
    var devide5 = j/5;
    var devide7 = j/7;
    if (Math.floor(devide7) !== devide7 ){
      if (Math.floor(devide2) !== devide2 ){
        if (Math.floor(devide3) !== devide3){
           if (Math.floor(devide5) !== devide5){
              prime.push(j);
             }
           }
        }
      }
  }
  var square = [];
  for ( var i = 0 ; i < prime.length ; i++){
    square.push(prime[i]*prime[i]);
  }
  var resultArr = [];
  for ( var k = 0 ; k < prime.length ; k++){
    if (square.indexOf(prime[k]) === -1){
      resultArr.push(prime[k]);
    }
  }
  
  var res = resultArr.reduce(function (a,b){return a+b;},0);
  return resultArr;
}

sumPrimes(977);


I know it won’t work for larger nums so I tried a General Solution but Nothing new! here is the new trail!


function sumPrimes(num) {
  var nums = [];
  var test = '' ;
  for (var i = 2 ; i <= num ;i++ ){
    nums.push(i);
  }
  var rrr = 'a';
  function fil (a){
    return a % 2 == 0;
  } 
   rrr = nums.filter(fil);
  return rrr ;
}

sumPrimes(10);

Hi Ahmed,

Here is a suggested algorithm I’d study a bit before implementing. It’s rather effective.

1 Like

Mate, U don’t know how much U helped me. <3 <3 <3 I owe U my Friend