js_code_golf_1_1.js

const prime1 = end => {
  const prime = [], num = [];
  let curr = 2, i = curr;
  while(i <= end) num.push(i++);
  while(num.length){
    prime.push(curr = num.shift());
    i = num.length;
    while(i--) if(num[i] % curr == 0) num.splice(i, 1);
    if(curr * curr > num[num.length - 1]) break;
  }
  return prime.concat(num);
}