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;  }}