json 数据 添加 删除 排序

js数据格式和json数据格式，各有各的用处，就个人而言，json更好用一点，js自身的数组和对像限制比较多。

以js的数组举例：

var a = ['1'];  
a[5] = 52;  
a.length    //这儿的结果是6，也就是说，中间的key会自动补全，而值呢，是undefined 

一，添加和删除

1，一维数组

test = {};                      //空json对像  
test['firstname'] = "tank";     //添加二个元素  
test['lastname'] = "zhang";  
console.log(test);              //查看  
  
delete test['lastname'];        //删除json中的某个元素  
console.log(test);  

2，二维数组

test1 = [{"name":"tank","total":"100"},{"name":"zhang","total":"23"},{"name":"hao","total":"325"}];  
add = {"name":"may"};  
  
test1.push(add);              //添加一个元素  
console.log(test1);    
  
delete test1[2];              //删除一个元素  
console.log(test1);  

二，排序

1，一维数组

test = ["100","23","325"];           //定义个数组  
  
function sortNumber(a,b)             //定义排序方法  
{  
     return a - b  
}  
  
test1_sort=test.sort(sortNumber);  
  
console.log(test1_sort);  

2，二维数组

test1 = [{"name":"tank","total":"100"},{"name":"zhang","total":"23"},{"name":"hao","total":"325"}];  
  
sort_by = function(field, reverse, primer){         //定义排序方法  
  
   var key = primer ?  
       function(x) {return primer(x[field])} :  
       function(x) {return x[field]};  
  
   reverse = [-1, 1][+!!reverse];  
  
   return function (a, b) {  
       return a = key(a), b = key(b), reverse * ((a > b) - (b > a));  
     }   
  
}  
  
test1_sort=test1.sort(sort_by('total', true, parseInt));    //根据total，升序排  
console.log(test1_sort);   
  
test1_sort=test1.sort(sort_by('name', false, ''));          //根据name，倒序排  
console.log(test1_sort);