栈，队列 in JavaScript

 1 // 在JavaScript里面，已经拥有push ,pop,shift,unshift的功能，但是，直接用太过简单。
 2 
 3 // 队列
 4 function Queue() {
 5     var arr = [];
 6     var size = 0;
 7 
 8     var push = function(num) {
 9         arr[size] = num;
10         size++;
11     };
12     var shift = function() {
13         var ret = arr[0];
14         for (var i = size-1;i>0;i--){
15             arr[i-1] = arr[i];
16         }
17         size--;
18         arr.length = size; // arr[size] = null;
19         return ret;
20     };
21     var get = function() {
22         return arr;
23     };
24 
25     var length = function() {
26         return size;
27     };
28 
29     return {
30         shift: shift,
31         push: push,
32         length: length,
33         get: get
34     };
35 };
36 var qu = new Queue();
37 qu.push(1);
38 qu.push(‘a‘);
39 qu.length(); //2 
40 qu.get(); // [1, "a"]
41 qu.shift(); //1
42 qu.get(); //["a"]
43 
44 
45 
46 // 栈
47 function Stock() {
48     var arr = [];
49     var size = 0;
50 
51     this.push = function(num) {
52         arr[size] = num;
53         size++;
54     }
55     this.pop = function() {
56         var ret = arr[--size];
57         arr[size] = null; //or arr.length = size;
59         return ret;
60     }
61     this.length = function() {
62         return size;
63     }
64     this.get = function() {
65         return arr;
66     }
67 };
68 var st = new Stock();