json的stringify和parse
ajax从后台取回的json数据是一个object，所以在success返回的data是可以直接取得他的属性的。stringify可以将object序列化，并且他还有筛选，改值等功能。parse可以将序列化的字符串解析成object，同样的他也有改值的功能
//我测试用的json串
{
"title": "test json",
"author": [
"sunny", "stella"
],
"edition": 3,
"year": 2014,
"response": true
}
//js代码及结果
$.ajax({
url: './test.json',
type: 'POST',
dataType: 'json',
data: {name: 'sunny'},
success: function(data){
var book = data;//data传过来的是object
console.log(book); //object
//序列化json成字符串
var jsonstringify = JSON.stringify(book);
console.log(jsonstringify);
//{"title":"test json","author":["sunny","stella"],"edition":3,"year":2014,"response":true}
$(".jsontext").text(jsonstringify);
//筛选字符串,只要author和year
var jsonchoose = JSON.stringify(book,["author","year"]);
console.log(jsonchoose);
//{"author":["sunny","stella"],"year":2014}
//可以在序列化的同时，改变其key的value方法，这里面相当于有个each
var jsonchoose1 = JSON.stringify(book,function(key, value){
if ( key == "author") {
value.push("smile");
return value;
}else if ( key == "year"){
return 2013;
}else{
return value;
};
});
console.log(jsonchoose1);
//{"title":"test json","author":["sunny","stella","smile"],"edition":3,"year":2013,"response":true}
//为了好看，还可以缩进个格式
var jsonchoose2 = JSON.stringify(book,null,4);
console.log(jsonchoose2);
//console可以看出来，但是页面是没有的
$(".jsontext").text(jsonchoose2);
//将序列化的字符串解析为对象
console.log(book.year); //2014
console.log(jsonchoose2.year);//undefined
var bookcopy = JSON.parse(jsonchoose2);
console.log(bookcopy);
//在parse的同时，改变其key的value方法,这里面相当于有个each
var bookcopy2 = JSON.parse(jsonchoose2, function(key, value){
if ( key == "author") {
value.push("tiger");
return value;
}else if ( key == "year"){
return 2015;
}else{
return value;
};
});
console.log(bookcopy2);
}
});