javascript指定排序方式

<pre name="code" class="javascript">    //测试数据       var data  = [{name:"zhangsan",age:21},{name:"lisi",age:22},{name:"wangwu",age:19}];      function createComparisonFunction(propertyName,orderBy_DESC){      return function (object1,object2){    var value1 = object1[propertyName]; var value2 = object2[propertyName]; if(orderBy_DESC){//降序if(value1>value2){return -1;}else if(value1<value2){return 1;}else{return 0;} }else{//默认升序 if(value1<value2){return -1;}else if(value1>value2){return 1;}else{return 0;} }   }   }   //指定排序方式，我这里是按照名字降序，第二个参数有值则降序，只传入第一个参数则升序   data.sort(createComparisonFunction("name",1))//打印结果   for(var i = 0 ;i<data.length;i++){document.write(data[i].name+"\n\n");   }