SOURCE

// const every = (arry,fn) => {
//   let result = true
//   for(let i = 0;i<arry.length;i++) {
//     result = result && fn(arry[i])
//   }
//   return result
// }
const every = (arry,fn) => {
  let result = true
  for(const value of arry) {
    result = result && fn(value)
  }
  return result
}
// console.log(every([NaN, NaN, NaN], isNaN))
// console.log(every([NaN, NaN, 4], isNaN))

const some = (arry,fn) => {
  let result = false
  for(const value of arry) {
    result = result || fn(value)
  }
  return result
}
// console.log(some([NaN, NaN, 2], isNaN))
// console.log(some([3, 3, 4], isNaN))

// var fruit = ['cherries', 'apples', 'bananas']
// console.log(fruit.sort())

// const sortBy = (property) => {
//   return (a,b) => {
//     var result = (a[property] < b[property]) ? -1 : (a[property] > b[property]) ? 1 : 0
//     return result
//   }
// }

var people = [
  {firstname: "aa",lastname:"bb"},
  {firstname: "cc",lastname:"dd"},
  {firstname: "ee",lastname:"ff"},
]

people.sort((a,b) => {
  return (a.firstname < b.firstname) ? -1 : (a.firstname > b.firstname ? 1 : 0)
})
console.log(people)