55. es6中some和find实现，优劣

[Guyidingsanyu]

Array.prototype._some = function(callback) {
  let flag = false
  for (let i = 0; i< this.length; i++) {
    flag = callback && callback(this[i])
  }
  return flag
}
let res = [1,2]._some(item => item > 2)
console.log(res)

[Guyidingsanyu]

// find实现
Array.prototype._find = function(callback) {
  let currentVal
  for(let i = 0; i < this.length; i++) {
    if (callback(this[i])){
      currentVal = this[i]
      break
    }
  }
  return currentVal
}
let res = [1, 2, 3]._find(item => item > 2)
console.log(res)