// ES5循环实现 some 方法
// ES5 loop implementation of some method
const selfSome = function (fn, context) {
  const arr = Array.prototype.slice.call(this)
  // 空数组直接返回 false，数组的 every 方法则相反返回 true
  // Empty arrays directly return false, while the every method of arrays returns true
  if (!arr.length)
    return false
  for (let i = 0; i < arr.length; i++) {
    if (!arr.hasOwnProperty(i))
      continue
    const res = fn.call(context, arr[i], i, this)
    if (res)
      return true
  }
  return false
}

Array.prototype.selfSome || (Object.defineProperty(Array.prototype, 'selfSome', {
  value: selfSome,
  enumerable: false,
  configurable: true,
  writable: true,
}))

const arr = [1, 2, 3, 4, 5]
console.log(arr.selfSome(item => item === 2))