In ES5 there were added a number of new Array methods, including Array.prototype.every(). With this method you can check all the items inside an array for a condition that's defined in a callback function. The method will return true if all items meet the conditions, but will return false as soon as it finds one item in the array that doesn't me…

every.js

var set1 = [2, 4, 6, 8, 10];
var set2 = [2, 4, 5, 8, 10];

console.log(set1.every(function (a) {
  return a % 2 === 0;
})); // true

console.log(set2.every(function (a) {
  return a % 2 === 0;
})); // false