JSON对象的stringify()和parse()方法

1、stringify() ---- JavaScript对象序列化为JSON字符串

     eg1.

     var book = {title: 'JS',

                        authors: ['Van'],

                        edition:3,

                        year:2011};

     var jsonText = JSON.stringify(book);

     默认情况下JSON.strigify(book)输出的JSON字符串不包含任何空格字符或缩进，因此保存在jsonText中的字符串如下：

     {"title":"JS","autors":["Van"],"edition":3,"year":2011}

    

     eg2.过滤结果

     var jsonText = JSON.stringify(book,["title","edition"]);

     返回结果：{"title":"JS","edition":3}

     eg3.过滤函数

     var jsonText = JSON.stringify(book,function(key,value){

           switch(key){

                case "authors": return value.join(",");

                case "year": return 5000;

                case "edition": return undefined;

                default: return value;

           }

     });

    返回结果：{"title":"JS","autors":"Van","year":5000}

2、parse() ---- 把JSON字符串解析为原生JavaScript值

     eg1.

     var bookCopy = JSON.parse(jsonText)；

     保存在bookCopy中即是book的内容

    

     eg2.解析选项

     在将日期字符串转换为Date对象时，经常要用到还原函数

     var book = {title: 'JS',

                        authors: ['Van'],

                        edition:3,

                        year:2011，

                        releaseDate:new Date(2011,11,1)};

    

     var jsonText = JSON.stringify(book);

     var bookCopy = JSON.parse(jsonText,function(key,value){

          if(key == "releaseDate"){ return new Date(value); }

          else{ return value; }

     });