Json.parse ()--json turn JS

JSON is typically used to exchange data with the server.

is typically a string when receiving server data.

We can use the Json.parse () method to convert data to JavaScript objects.

Grammar

Json.parse (text[, Reviver])

Parameter description:

• text: required, a valid JSON string.
• reviver: Optional, a function that transforms the result, which will call this function for each member of the object.

JSON Parsing Instance

For example, we received the following data from the server:

{"Name": "Runoob", "Alexa": 10000, "site": "Www.runoob.com"}

We use the Json.parse () method to process the above data and convert it to a JavaScript object:

var obj = json.parse (' {' name ': ' Runoob ', ' Alexa ': 10000, ' site ': ' www.runoob.com '} ');

Once the parsing is complete, we can use the JSON data on the Web page:

For example:

<PID= "Demo"></P> <Script>varobj=Json.parse ('{"name": "Runoob", "Alexa": 10000, "site": "Www.runoob.com"}');d Ocument.getelementbyid ("Demo"). InnerHTML=Obj.name+ ":" +Obj.site;</Script>

Receiving JSON data from the server

We can use AJAX to request JSON data from the server and parse it into JavaScript objects.

var xmlhttp = new XMLHttpRequest (); xmlhttp.onreadystatechange = function () {    if (this.readystate = = 4 && this. Status = = $) {        MYOBJ = Json.parse (this.responsetext);        document.getElementById ("Demo"). InnerHTML = Myobj.name;    }}; Xmlhttp.open ("GET", "/try/ajax/json_demo.txt", true); Xmlhttp.send ();

Receiving JSON data from the service side of an array

If the JSON data for an array is received from the server, Json.parse converts it to a JavaScript array:

Exception parsing data

JSON cannot store Date objects.

If you need to store a Date object, you need to convert it to a string.

The string is then converted to a Date object.

L For example:

var text = ' {' name ': ' Runoob ', ' initdate ': ' 2013-12-14 ', ' site ': ' www.runoob.com '} '; var obj = json.parse (text); O Bj.initdate = new Date (obj.initdate); document.getElementById ("Demo"). InnerHTML = Obj.name + "Date Created:" + obj.initdate;

We can enable json.parse for the second parameter reviver, a function that transforms the result, which each member of the object calls this function.

var text = ' {' name ': ' Runoob ', ' initdate ': ' 2013-12-14 ', ' site ': ' www.runoob.com '} '; var obj = json.parse (text, function (ke Y, value) {    if (key = = "Initdate") {        return new Date (value);    } else {        return value;}}); document.getelemen Tbyid ("Demo"). InnerHTML = Obj.name + "Date Created:" + obj.initdate;

Analytic functions

JSON does not allow a function to be included, but you can store the function as a string and then convert the string to a function.

var text = ' {' "name": "Runoob", "Alexa": "function () {return 10000;}", "Site": "www.runoob.com"} '; var obj = json.parse (text) ; obj.alexa = eval ("(" + Obj.alexa + ")"); document.getElementById ("Demo"). InnerHTML = Obj.name + "Alexa rank:" + obj.alexa ();

Browser support

The Json.parse () function is supported by mainstream browsers:

• Firefox 3.5
• Internet Explorer 8
• Chrome
• Opera 10
• Safari 4

Json.parse ()--json turn JS