Typescript Queue

gistfile1.txt

interface Collection {
  push(value: number): void;
  pop(): number;
  peek(): number;
  isEmpty(): boolean;
}

class Node {
  value: number;
  constructor(value: number) {
    this.value = value;
  }
}

class Queue implements Collection {
  pointer: any;
  rear: any;
  constructor(value: number) {
    this.pointer = null;
    this.rear = null;
  }
  push(value: number) {
    var pushedNode = new Node(value);
    var previousRear = this.rear;
    if (!this.rear) {
      this.pointer = pushedNode;
      this.rear = pushedNode;
    } else {
      this.rear = pushedNode;
      previousRear.pointer = pushedNode;
    }
  }
  pop() {
    var poppedValue = this.pointer.value;
    this.pointer = this.pointer.pointer;
    if (!this.pointer) {
      this.rear = null;
    }
    return poppedValue;
  }
  peek() {
    if (this.pointer) {
      return this.pointer.value;
    } else {
      return undefined;
    }
  }
  isEmpty() {
    return this.rear === null;
  }
}

var queue = new Queue();
queue.push(1);
queue.push(2);
queue.push(3);
queue.pop();
queue.pop();
queue.pop();
console.log(queue)
console.log(queue.peek())
console.log(queue.isEmpty())

Don't know why the constructor for Queue takes a value, but thanks for laying the groundwork.