5.4. Every and then some.js

// Your code here.
function every(arr, f) {
  for (var i = 0; i < arr.length; i++) {
    if (!f(arr[i])) {
      return false;
    }
  }
  return true;
}

function some(arr, f) {
  for (var i = 0; i < arr.length; i++) {
    if (f(arr[i])) {
      return true;
    }
  }
  return false;
}

console.log(every([NaN, NaN, NaN], isNaN));
// → true
console.log(every([NaN, NaN, 4], isNaN));
// → false
console.log(some([NaN, 3, 4], isNaN));
// → true
console.log(some([2, 3, 4], isNaN));
// → false