走进 Typescript 数据结构（字典）

typescript-cover-image.jpg

集合、字典和散列表可以存储不重复的值。字典和集合相似，集合以[值，值]的形式存储元素，字典是以[键，值]的形式来存储元素，字典也叫做映射

• set(key,value) 添加元素

  set(key: any, val: any) {
    this.items[key] = val;
  }

• delete(key) 通过键删除元素

  delete(key: any): boolean {
    if (this.has(key)) {
      delete this.items[key];
    }
    return false;
  }

• has(key) 根据键判断某个元素是否存在于字典

  has(key: any): boolean {
    return this.items.hasOwnProperty(key);
  }

• values() 将所有元素以数组形式返回

values(): any[] {
    let values: any[] = [];
    for (let k in this.items) {
      if (this.has(k)) {
        values.push(this.items[k]);
      }
    }
    return values;
  }

完整代码

export default class Dictionary {
  items: object;
  constructor() {
    this.items = {};
  }
  has(key: any): boolean {
    return this.items.hasOwnProperty(key);
  }
  set(key: any, val: any) {
    this.items[key] = val;
  }
  delete(key: any): boolean {
    if (this.has(key)) {
      delete this.items[key];
    }
    return false;
  }
  get(key: any): any {
    return this.has(key) ? this.items[key] : undefined;
  }
  values(): any[] {
    let values: any[] = [];
    for (let k in this.items) {
      if (this.has(k)) {
        values.push(this.items[k]);
      }
    }
    return values;
  }
}

测试代码

let dic = new Dictionary();
dic.set("angular", "javascrip");
dic.set("spring", "java");
dic.set("flask", "python");

console.log(dic.values());