js jq 字符串数组对象

数组是有序的，对象是无序，数组是特殊的对象

数组

声明数组

var arr=new Array('red','blue','yellow');  //["red", "blue", "yellow"]

var arr=["red", "blue", "yellow"];

var arr=new Array();

     arr[0]='red';

     arr[1]='blue';

     arr[2]='yellow';

追加一个元素

arr.push('green');   //["red", "blue", "yellow","green"]

获取数组的元素个数

var len=arr.length;

length的长度是根据索引得来

arr['name']='xiaozhu';

arr.length   //

arr[8]='xiaozhu';

arr.length   //

对象

声明对象

var person = new Object();

    person.name = "xiaozhu";

    person.age = 21;

    var person = {

        name: "xiaozhu",

        age : 21

    }

//{name: "xiaozhu", age: 21}

字符串数组数组格式化（对象）

字符串转数组

var str="a,s,d";

var arr = str.split(',');         // ["a","s","d"]  数组

数组转数组格式化（字符串）

str = JSON.stringify(arr);        // ["a","s","d"]  字符串

数组格式化（字符串）转数组

arr = JSON.parse(str );          // ["a","s","d"]  数组

JSON字符串转换为JSON对象
var str = '{ "name": "cxh", "sex": "man" }';

var obj = eval('(' + str + ')');    //{name: "cxh", sex: "man"}   对象
var obj =jQuery.parseJSON(); 
var obj = JSON.parse(str);

JSON对象转换为JSON字符串

var str = { "name": "cxh", "sex": "man" };

str = JSON.stringify(str ); //{name: "cxh", sex: "man"}   字符串

数组转字符串

var arr=["a","s","d"];

var str =arr.join(',');         // a,s,d     字符串

var str=arr.toString();         //a,s,d 字符串

循环遍历

 遍历数组

 var arr=["a","b","c"];

　$.each(arr,function(i,item){

        console.log(i+"--"+item);

 });

 遍历对象

  var obj={name:"xiaozhu",age:20};

  $.each(obj,function(i,item){

        console.log(i+"--"+item);

 });

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js jq 字符串数组对象

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