var  params = [];  

    for(var i = 0; i < 3; i++){  

        var param = [];  

        param.push("one");  

        param.push("two");  

        param.push("three");  

        params.push({"group":i,"param":param});  

    }  

   组成的json串：  

   [{"group":0,"param":["one","two","three"]},{"group":1,"param":["one","two","three"]},{"group":2,"param":["one","two","three"]}]  

JS实现在JSON数组开头插入（拼接）一个元素