const xs = [1, 2, 3, 4, 5]
const ys = [1, 2, 'a', 4, 5]

const areXsIntegers = xs.every(Number.isInteger)
const areYsIntegers = ys.every(Number.isInteger)

console.log(areXsIntegers) // true
console.log(areYsIntegers) // false