数组自定义unshift和去重

arr = [1, 2, 4, 5]
arrObj = Object.assign([], arr)
//自定义实现数组 unshift
Array.prototype.myunshift = function (...eles) {
  const len = this.length
  for (let i = 1; i <= len; i++) {
    arr[i] = arrObj[i - 1]
  }
  var args = Array.from(eles);
  arr[0] = args.pop()
  arrObj = Object.assign([], this)
  if (args.length > 0) {
    this.length = len + 1
    this.myunshift(...args)
  }

  return len + arguments.length
}

Array.prototype.myunshift1 = function () {
  const len = arguments.length
  for (let i = len - 1; i >= 0; i--) {
    const ele = arguments[i]
    this.splice(0, 0, ele)
  }
  return this.length
}
// ret = arr.myunshift1(8, 7, 5)
// console.log(arr, ret)

arr1 = [1, 3, 4, 5, 7, 3, 5]
//数组去重
Array.prototype.myUnique = function () {
  //return Array.from(new Set(this))
  const retArr = []
  for (let i = 0; i < this.length; i++) {
    if (!retArr.includes(this[i])) {
      retArr.push(this[i])
    }
  }
  return retArr
}
console.log(arr1.myUnique())