jquery JSON parsing method example introduction_jquery

What is considered here is that the server returns a JSON string. For JSON objects encapsulated by plug-ins such as JSONObject, the same is true and will not be explained here.

The JSON string set is first given here. The string set is as follows:

var data=" 
{ 
root: 
[ 
{name:'1',value:'0'}, 
{name:'6101',value:'西安市'}, 
{name:'6102',value:'铜川市'}, 
{name:'6103',value:'宝鸡市'}, 
{name:'6104',value:'咸阳市'}, 
{name:'6105',value:'渭南市'}, 
{name:'6106',value:'延安市'}, 
{name:'6107',value:'汉中市'}, 
{name:'6108',value:'榆林市'}, 
{name:'6109',value:'安康市'}, 
{name:'6110',value:'商洛市'} 
] 
}";

Based on the data types jquery asynchronously obtains - json objects and strings, here we introduce the result processing methods obtained in two ways.

1. For the JSON string returned by the server, if the jquery asynchronous request does not have a type description, or is accepted as a string, then it needs to be objectified. The method is not too troublesome, that is, put the string in eval () is executed once. This method is also suitable for obtaining json objects using ordinary javascipt. The following is an example:

var dataObj=eval("("+data+")");//转换为json对象 
alert(dataObj.root.length);//输出root的子对象数量 
$.each(dataObj.root,fucntion(idx,item){ 
if(idx==0){ 
return true; 
} 

//输出每个root子对象的名称和值 
alert("name:"+item.name+",value:"+item.value); 
})

Note: For general js to generate json objects, you only need to replace the $.each() method with a for statement, and the others remain unchanged.

2. For the JSON string returned by the server, if the jquery asynchronous request sets the type (usually this configuration attribute) to "json", or uses the $.getJSON() method to obtain the server return, then there is no need to eval ( ) method, because the result obtained at this time is already a json object, you only need to call the object directly. Here, the $.getJSON method is used as an example to illustrate the data processing method:

$.getJSON("http://gaoyusi.blog.163.com/",{param:"gaoyusi"},function(data){

//此处返回的data已经是json对象 
//以下其他操作同第一种情况 
$.each(data.root,function(idx,item){ 
if(idx==0){ 
return true;//同countinue，返回false同break 
} 

alert("name:"+item.name+",value:"+item.value); 

}); 
});