js------数组随机排序和去重

let arr = ['g', 'b', 'c', 'd', 'e', 'a', 'g', 'b', 'c'];

// 数组随机排序(原数组被修改)
Array.prototype.randomSort = function () {
  const len = this.length;
  for (let i = len - 1; i > 1; i--) {
    let n = Math.floor(Math.random() * i);
    let lastone = this[i];
    this[i] = this[n];
    this[n] = lastone;
  }
};

// 数组去重(返回新数组)
Array.prototype.removeDuplicate = function () {
  let obj = {};
  const len = this.length;
  for (let i = 0; i<len; i++) {
    if (obj[this[i]]) continue;
    obj[this[i]] = this[i];
  }
  return Object.keys(obj);
};

// 用法
arr.removeDuplicate();
arr.randomSort();