LINQ to JavaScript 之GroupBy的实现

前几天，我的Leader 要我给一串  数组 进行统计！！

因为在数据里做group by太麻烦了，所以要在javascript里面实现。

于是我 想到了 LINQ to JavaScript  ，但 细细的看了一下 ，发现没有group by的相关功能，于是自己动手搞了一下！

 

这个 功能 是完全基于 LINQ to JavaScript的，只不过自己添加了group by的功能，与其他功能可以一起使用！

 

代码实现:

 

 需要分组的数据：

 

var samples =[
               {_C:"000001",_S:"SFZA",_N:"深发展A"},
               {_C:"000001",_S:"WKA",_N:"万科A"},
               {_C:"000001",_S:"PTJTA",_N:"PT金田A"},
               {_C:"000001",_S:"STGN",_N:"ST国农"},
               {_C:"000001",_S:"SJXY",_N:"世纪星源"},
               {_C:"000001",_S:"SZYA",_N:"深振业A"},
               {_C:"000001",_S:"STDS",_N:"ST达声"},
               {_C:"000001",_S:"STBLL",_N:"ST宝利来"},
               {_C:"000001",_S:"ZGBA",_N:"中国宝安"},
               {_C:"000011",_S:"SSTHX",_N:"SST华新"},
               {_C:"000011",_S:"SSTWY",_N:"S*ST物业"},
               {_C:"000011",_S:"NBA",_N:"南玻A"},
               {_C:"000011",_S:"STSHA",_N:"*ST石化A"},
               {_C:"000011",_S:"SHGF",_N:"沙河股份"},
               {_C:"000011",_S:"PTZHA",_N:"PT中浩A"},
               {_C:"000011",_S:"SKJA",_N:"深康佳A"},
               {_C:"000011",_S:"SSTZHA",_N:"SST中华A"},
               {_C:"000011",_S:"STZGA",_N:"ST中冠A"},
               {_C:"000011",_S:"SSBA",_N:"深深宝A"},
               {_C:"000021",_S:"STHFA",_N:"ST华发A"},
               {_C:"000021",_S:"CCKF",_N:"长城开发"},
               {_C:"000022",_S:"SCWA",_N:"深赤湾A"},
               {_C:"000023",_S:"STDA",_N:"深天地A"}
]

 

   使用代码：

 

 

  var samples1 = From(EALists).
                            GroupBy(function(item,index){ return item._C;});

 

代码实现：

Array.prototype.GroupBy=function(clause){
  var newArray=new Array();
        if(typeof(clause) == "function")
            {
                for (var index = 0; index < this.length; index++)
                {

                   var KeyValues= clause(this[index], index);
                    var isExsits=false;
                    
                    for(var n=0;n<newArray.length;n++)
                       {
                          if(newArray[n].KeyValue==KeyValues)
                          {
                             newArray[n].KeyCount=parseInt(newArray[n].KeyCount)+1;
                             isExsits=true;
                          }
                       }
                       if(!isExsits)
                       {
                         newArray.push({KeyValue:KeyValues,KeyCount:1});
                       }
                   
                }
            }
          return newArray;
};