JSON string-to-JSON object conversion

JSON (JavaScript object Notation) JS objects symbol

is a lightweight format for data interchange

JavaScript eval () function implementation

(i) standard format

function jsonformatting () {    var jsonstring = '{' Unid ': ' 1 ', ' CustomerName ': ' Song Jiang ', ' age ':' ""} ';    var jsonobject = eval ('('jsonstring') ');    var tt = ';    $.each (Jsonobject,function (k, v) {        tt + = k + ":" + v+ "<br/>";    });    $ ("#divmessage"). HTML (TT); }

The notation is that the key value is surrounded by double quotes. This format can be called a json string. converts a JSON string to a JSON object through the Eval function .

(ii) abbreviated format

function jsonformatting () {    var jsonstring = '{Unid: ' 1 ', CustomerName: ' Song Jiang ', Age:' "} ';    var jsonobject = eval ('('jsonstring') ');    var tt = ';    $.each (Jsonobject,function (k, v) {        tt + = k + ":" + v+ "<br/>";    });    $ ("#divmessage"). HTML (TT); }

The key value omits the quotation marks and converts the JSON string into a JSON object through the Eval function, which can then be accessed in two ways:

@1. Dot Syntax object.property

var jsonstring = ' {' Unid ': ' 1 ', ' CustomerName ': ' Song Jiang ', ' Age ': ' ""} '; var jsonobject = eval (' (' + jsonstring + ') '); Alert (  Jsonobject.customername);

@2. Index of key-value pairs

Object[key]

var jsonstring = ' {' Unid ': ' 1 ', ' CustomerName ': ' Song Jiang ', ' Age ': ' ""} '; var jsonobject = eval (' (' + jsonstring + ') '); Alert ( jsonobject["CustomerName"]);

eval function Description:

It can execute a string as if it were a JavaScript expression.

The Eval function receives a parameter s, and if s is not a string, it returns s directly. Otherwise, the S statement is executed.

If the S statement execution result is a value, this value is returned, otherwise undefined is returned. Object declaration syntax '{} ' does not return a value , it needs to be enclosed in parentheses to return a value.

function Evaltest () {    var code1 = ' A ' + 2 ';    Expression    var Code2 = ' {a:2} ';      Statement    alert (eval (code1));     Output A2    alert (eval (code2));     Output undefined    alert (eval (' (' + Code2 + ') ');//Output [Object Object]}

　

For an object declaration statement, it is only execution and cannot return a value.

In order to return an object declaration statement such as a commonly used "{}", it must be enclosed in parentheses to convert it to an expression in order to return its value.

Adds a conversion method from JSON strings to JSON objects for jquery.

Open the library and locate Jquery.extend ({

Add method

Jsontoobject:function (a) {     return eval (' (' + A + ') ');     

Use the following:

var jsonstring = ' {' Unid ': ' 1 ', ' CustomerName ': ' Song Jiang ', ' Age ': ' ""} '; var jsonobject = $.jsontoobject (jsonstring); alert ( jsonobject["CustomerName"]);

Where jsonstring is a json string, and Jsonobject is a JSON object

jquery implementation

$.parsejson ("Jsonstr"); Convert a JSON string to a JSON object

Using the Json.js Package plugin

var obj = json.parse (Strjson);

JSON object to JSON string

var str = json.stringify (obj) needs to import Json.js package

function jsonformatting () {            var jsonobject = {"Unid": "1", "CustomerName": "Song Jiang", "Age": "$"};                        var jsstr=json.stringify (jsonobject);            Alert (typeof jsstr);                               }

　　

JSON string-to-JSON object conversion