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);
别看是小问题,但是如果长时间不用,也会生疏,或者忘了。
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