封装一个Mymap和Myset

class MyMap {

  constructor() {

    this.dict = {};

    this.size = 0;

  }

  updateSize() {

    this.size = Object.keys(this.dict).length;

  }

  set(key, value) {

    this.dict[key] = value;

    this.updateSize();

  }

  delete(key) {

    delete this.dict[key];

    this.updateSize();

  }

  clear() {

    this.dict = {};

    this.size = 0;

  }

  get(key) {

    return this.dict[key];

  }

  has(key) {

    return Object.keys(this.dict).includes(key);

  }

  keys() {

    return Object.keys(this.dict);

  }

  values() {

    return Object.keys(this.dict).map((key) => this.dict[key]);

  }

  entries() {

    return Object.keys(this.dict).map((key) => [key, this.dict[key]]);

  }

  forEach(handler){

      for(let key in this.dict){

          handler.apply(this,[this.dict[key],key,this])

      }

  }

}

!(function () {

  const map = new MyMap();

  /* 增加数据 */

  map.set("six", "陆小凤");

  map.set("seven", "洪七公");

  map.set("eight", "袁八爷");

  /* 修改与增加一样 */

  map.set("seven", "白景琦");

  /* 删除数据 */

  //   map.delete("eight");

  //   map.clear()

  /* 查询数据 */

  console.log(map.get("six"));

  console.log(map.get("seven"));

  console.log(map.get("eight"));

  /* 更多查询 */

  console.log(map.size);

  /* 查询有无键值 */

  console.log(map.has("seven"));

  console.log(map.has("nine"));

  /* 查询所有的键或值 */

  console.log(map.keys());

  console.log(map.values());

  console.log(map.entries());

  /* 遍历迭代器（iterators） */

  for (const iterator of map.entries()) {

    console.log(iterator);

  }

  /* 遍历 */

  map.forEach(

      (value, key, m) => console.log(key, value)

  );

})();

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

class MySet {

  constructor(arr = []) {

    this.arr = arr.filter((item, index) => arr.indexOf(item) === index);

    this.size = this.arr.length;

  }

  updateSize() {

    this.size = this.arr.length;

  }

  add(value) {

    if (!this.arr.includes(value)) {

      this.arr.push(value);

      this.updateSize();

    }

  }

  delete(value) {

    for (let i = 0; i < this.arr.length; i++) {

      if (this.arr[i] === value) {

        this.arr.splice(i, 1);

        this.updateSize();

        break;

      }

    }

  }

  clear() {

    this.arr = [];

    this.updateSize();

  }

  has(value) {

    return this.arr.find((item) => item === value) !== undefined;

  }

  forEach(handler) {

    for (let i = 0; i < this.arr.length; i++) {

      handler.apply(this, [this.arr[i], i, this]);

    }

  }

  keys() {

    return this.arr;

  }

  values() {

    return this.arr;

  }

  entries() {

    return this.arr.map((item) => ({ [item]: item }));

  }

  toArray() {

    return this.arr;

  }

}

!(function () {

  // const set = new Set()

  const set = new MySet([3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5, 8]);

  console.log(set.size);

  /* 数据已经实现了去重 */

  /* CRUD */

  set.add(10);

  set.add(10);

  set.delete(5);

  // set.clear()

  console.log(set.has(3));

  console.log(set.has(11));

  set.forEach((value, index) => console.log(value, index));

  console.log(set.keys());

  console.log(set.values());

  console.log(set.entries());

  for (const iterator of set.values()) {

    console.log(iterator);

  }

})();