js实现栈

stackfirst-in-last-out用数组模拟栈实现classStack{constructor(){this.items=[]}}1.插入方式push(element){this.items.push(element)}2.释放方法pop(){returnthis.items.pop()}3.获取栈顶元素peek(){returnthis.items[this.items.length-1]}4.判断是否为空isEmpty(){returnthis.item.length===0}5.清空clear(){this.items=[]}6.获取长度size(){returnthis.items.length}