JavaScript 数据结构（3）：循环队列 CircularQueue

/** * 循环队列(Circular Queue) * 先进先出 */// Array 实现function CirQueue (s) {    var maxSize = s || 5,        arr = new Array(maxSize),        front = 0,        end = -1,        size = 0;    return {        insert: function(item){         // 入列            if(size < maxSize){                if(end == maxSize -1){                    end = -1;                }                arr[++end] = item;                size++;            }else{                console.log('Queue is full!');            }        },        remove: function(){         // 出列            if(size > 0){                var temp = arr[front++];                if(front == maxSize){                    front = 0;                }                size--;                return temp;            }            console.log('Queue is empty!');            return undefined;        },        peek: function(){       // 查看队头            return arr[front];        },        isEmpty: function(){        // 队列是否为空            return size === 0;        },        isFull: function(){         // 队列是否已满            return size === maxSize;        },        size: function(){           // 队列长度            return size;        }    };}var queue = new CirQueue(3);console.log(queue.remove());queue.insert(1);queue.insert(2);queue.insert(3);queue.insert(4);while(!queue.isEmpty()){    console.log(queue.remove());}