javascript 跳跃式前进 (3) - 跳入 JSON

JSON崛起不是意外,是顺应时代;相当简洁小巧的书写模式及阅读方式;

var person = {
    "name" :"CRPER",
    "age" : 24,
    "Interesting" :['reading','play'] 
}
var person_str = JSON.stringify(person);   //这一步就是把JSON对象转为相应的字符串
console.log(person_str);   //打印值 :　{"name":"CRPER","age":24,"Interesting":["reading","play"]}
console.log(typeof person_str)；   //打印值: "string"
/*
 过滤:第二个参数(riviver)支持传入一个数组或者一个函数来过滤整个json对象不需要的属性和值
 默认需要返回自身value[就是条件不成立的时候]
*/
var person1 = JSON.stringify(person,["age","Interesting"]);
console.log(person1);  //打印值:{"age":24,"Interesting":["reading","play"]}
var person2 = JSON.stringify(person,function(key,value){
   switch(key){
       case "name" :return  value + "LIN";
       case "age":return  parseInt(value) + 1;
       default : return value;
   }
})
console.log(person2);   //打印值: "{"name":"CRPERLIN","age":25,"Interesting":["reading","play"]}"
var person2 = JSON.stringify(person,function(key,value){
   if(key == "name"){
     return "LIN" + value;
   }else if(key == "age"){
      return 10+value;
   }
   else{
      return value
   }
})
console.log(person2);  //打印值: "{"name":"LINCRPER","age":34,"Interesting":["reading","play"]}"
/*缩进:第三个参数是控制缩进的,最大的缩进为10个字符*/
var person3 = JSON.stringify(person,null,4);
console.log(person3);
/*
"{
    "name": "CRPER",
    "age": 24,
    "Interesting": [
        "reading",
        "play"
    ]
}"
*/
/*
 toJSON方法,函数过滤器的补充;
 1. 若对象内有toJSON,则优先执行,无则返回自身;
 2. 若作为第二个参数传入,则对函数进行过滤
*/
var book = {
   "title" : "JS大神进阶记",
   "page_total":999,
   "money":99,
   "copyright":"CRPER",
   toJSON:function(){
       return this.title;
  }
}
var test = JSON.stringify(book);   
console.log(test);      //打印值:""JS大神进阶记""
var test2 = JSON.stringify(book,function(key,value){
    console.log(value) ;   //JS大神进阶记
});

//接着上面的例子;
  var parseJSON = JSON.parse(person_str);     //把符合书写规范的字符串转为对象
  console.log(parseJSON);    //打印值:  Object {name: "CRPER", age: 24, Interesting: Array[2]}