const gcf = (n1, n2) => {

  let gcf = 0;
  let limiter = n1 > n2 ? n1:n2

  for(i = 1; i <= limiter; i++){
    if(n1 % i == 0 && n2 % i == 0 ){
      gcf = i;
    }
  }
  return gcf;
}

console.log(gcf(8, 12));