json生成器

最近的项目需要模拟一个json格式的数据，
格式如下

{
    "studentA": [
        {
            "grade": "A",
            "class": "B",
            "course": {
                "a": "0-100",
                " b ": "0-100"
            }
        }
    ],
    "studentB": [
        {
            "grade": "A",
            "class": "B",
            "course": {
                "a": "0-100",
                " b ": "0-100"
            }
        }
    ]
}

我们要实现这个功能，
1、变量和数组声明

var score= new Array();
            var num1=d3.range(6).map(d3.random.normal(0.8,0.1));
             // 随机生成年级
            var grades=[1,2,3,4];
            // 随机生成班级
            var classes=[1,2];
            //随机生成姓
            var lastnames=["赵","钱","孙","李","周","吴","郑","王","冯","陈","卫","蒋","沈","韩","杨","朱","秦","许","何","吕","施","张"];
            //随机生成名
            var firstnames=["伟","芳","娜","丽","强","静","敏","磊","军","涛","明","刚","洁","斓","文","华","金","斌","波","辉","亮","超"];

2、构造函数

function getStu(){
                var stu = {
                    "name":"",
                    "detail":{}
                };
                var lastname=lastnames[Math.floor(Math.random()*lastnames.length+1)-1];
                var firstname=firstnames[Math.floor(Math.random()*firstnames.length+1)-1];
                var grade=Math.floor(Math.random()*4+1);
                var classe=Math.floor(Math.random()*2+1);
                stu.name = lastname+firstname;
                stu.detail.grade = grade;
                stu.detail.class = classe;
                stu.detail.score = num1.map(function(d){
                    return d*100>100?100:Math.round(d*100);
                });
                return stu;
            }

下面我们用innerHTML给页面中写入内容：

temp.innerHTML='
                <div id="copy">
                    {<br>
                        <span>
                        "<label></label>":[ 
                        <br>&nbsp; {
                            <br>
                            &nbsp;&nbsp; "grade":"<label></label>",<br>
                            &nbsp;&nbsp; "class":"<label></label>",<br> 
                            &nbsp;&nbsp; "course":{<br>
                                &nbsp;&nbsp;&nbsp;"计算机网络":"<label></label>",<br>
                                &nbsp;&nbsp;&nbsp;"大学英语":"<label></label>",<br>
                                &nbsp;&nbsp;&nbsp;"Web前端开发":"<label></label>",<br>
                                &nbsp;&nbsp;&nbsp;"C语言程序设计":"<label></label>",<br>
                                &nbsp;&nbsp;&nbsp;"数据结构":"<label></label>",<br>
                                &nbsp;&nbsp;&nbsp;"大学物理":"<label></label>",<br>
                                &nbsp;&nbsp; }
                                <br>
                                &nbsp; }<br>
                                ],<br>
                        </span>}
                </div>';
                temp.getElementsByTagName("label")[0].innerHTML=stu.name;
                temp.getElementsByTagName("label")[1].innerHTML=stu.detail.grade;
                temp.getElementsByTagName("label")[2].innerHTML=stu.detail.class;
                temp.getElementsByTagName("label")[3].innerHTML=stu.detail.score[0];
                temp.getElementsByTagName("label")[4].innerHTML=stu.detail.score[1];
                temp.getElementsByTagName("label")[5].innerHTML=stu.detail.score[2];
                temp.getElementsByTagName("label")[6].innerHTML=stu.detail.score[3];
                temp.getElementsByTagName("label")[7].innerHTML=stu.detail.score[4];
                temp.getElementsByTagName("label")[8].innerHTML=stu.detail.score[5];
                document.getElementById("main").appendChild(temp);
                 }