JS 实现Map

function Map() {
    this.arr = new Array();
    var struct = function(key, value) {
        this.key = key;
        this.value = value;
      };
    this.put = function(key, value){
          for (var i = 0; i < this.arr.length; i++) {
              if ( this.arr[i].key === key ) {
                 this.arr[i].value = value;
                  return;
               }
          }
       this.arr[this.arr.length] = new struct(key, value);
    };
    this.get = function(key) {
       for (var i = 0; i < this.arr.length; i++) {
          if ( this.arr[i].key === key ) {
               return this.arr[i].value;
          }
      }
      return null;
     };
     this.values=function(){
        var value=[]
       for (var i = 0; i < this.arr.length; i++) {
          value.push(this.arr[i].value);
       }
       return value.join(",");
     };
     this.remove = function(key) {
       var v;
       for (var i = 0; i < this.arr.length; i++) {
          v = this.arr.pop();
          if ( v.key === key ) {
           continue;
       }
       this.arr.unshift(v);
      }
     };
     this.size = function() {
      return this.arr.length;
     };
     this.isEmpty = function() {
         return this.arr.length <= 0;
     };
  }
  var map = new Map();
  map.put("a","aaaaaaaaaaaaaaa");
  map.put("b","bbbbbbbbbbb");
  map.put("c","cccccccccccccc");
  map.remove("b");
  console.info(map.values());