关于数据结构:数据结构js实现队列

class Queue {constructor() {
    this.count = 0;
    this.lowestCount = 0;
    this.items = {};}

  isEmpty() {return this.count === this.lowestCount;}

  enqueue(element) {this.items[this.count] = element;
    this.count++;
  }

  dequeue() {if (this.isEmpty()) {return void 0;}
    const result = this.items[this.lowestCount];
    delete this.items[this.lowestCount];
    this.lowestCount++;
    return result;
  }

  // 查看第一个元素
  peek() {if (this.isEmpty()) {return void 0;}
    return this.items[this.lowestCount];
  }

  size() {return this.count - this.lowestCount;}

  clear() {
    this.count = 0;
    this.items = {};
    this.lowestCount = 0;
  }

  toString() {if (this.isEmpty()) {return "";}

    let result = this.peek();
    for (let i = this.lowestCount + 1; i < this.count; i++) {result += `,${this.items[i]}`;
    }
    return result;
  }
}