JSON data acceptance in JavaScript, processing introduction

JS Way to read JSON I have two kinds of contacts:

Method One: Function construction definition method returns

The code is as follows	Copy Code
var Strjson = "{name: ' JSON name '}";//Get JSON var obj = new Function ("return" + Strjson) ()//converted JSON object alert (obj.name);//json name

Method Two: The famous eval function in JS

The code is as follows	Copy Code
var Strjson = "{name: ' JSON name '}";//Get JSON var obj = eval ("(+ Strjson +)");//Converted JSON object alert (obj.name);//json name

The second way to be aware of this is that the object expression {' name ': ' JSON name '} must be extended with ' () ' otherwise

The code is as follows	Copy Code
var Strjson = "{name: ' JSON name '}"; var obj = eval (Strjson); alert (obj.constructor);//string constructor alert (obj.name);//undefine

An object expression must be extended to eval execution to generate an anonymous object!

JS receives JSON data across domains

PHP Script Service side

The code is as follows	Copy Code
<?php if (Isset ($_get[' callback ')) &&!empty ($_get[' callback ')) { Echo $_get[' callback ']. ' ({"name": "Snow Residual Love", "profession": "Phper"}) '; } ?>

$_get[' Callback ' is the name of the JS function to be invoked on the client, {"name": "Snow Residue", "profession": "Phper"} is the JSON data returned by the server.

Four, JS client

The code is as follows	Copy Code
<script type= "Text/javascript" > function func (data) { Alert (' Name: ' + data.name + ', Occupation: ' + data.profession '); } </script> <script type= "Text/javascript" src= "/technology/jsonp/server.php?callback=func" ></script>

You can do it locally, the result will pop up "name: Snow Phper, Occupation:".

Five, jquery application

The Getjson function of jquery has integrated cross-domain access by following a parameter in the address of the URL, with a placeholder instead of the parameter value, as shown below, where jquery automatically replaces the placeholder with the function name of the timestamp at execution time.

The code is as follows	Copy Code
<script type= "Text/javascript" src= "/js/jquery-1.3.2.min.js" ></script> <script type= "Text/javascript" > $.getjson ('/technology/jsonp/server.php?callback=? ', function (data) { Alert (' Name: ' + data.name + ', Occupation: ' + data.profession '); }); </script>

We need to process JSON data after acceptance.

The code is as follows

Copy Code

function Showuserlist () { Postxmlhttp ("./userlistservlet.do", "Usercallback (Resultvalue)", "Loading ()"); } function Usercallback (jsondate) { JSON data serialized into a JS object var jsobject = eval (' (' +jsondate+ ') '); var htmlstr = "<table align=center width=60%>" + "<tr>" + "<th> user id</th><td> password </td><td> username </td><td> location </td><td> operation </td> "+ "</tr>"; for (Var i=0;i<jsobject.length;i++) { htmlstr+= "<tr id= ' tr" +i+ "' >" + "<td>" +jsobject[i].userid+ "</td>" + "<td>" +jsobject[i].pword+ "</td>" + "<td>" +jsobject[i].username+ "</td>" + "<td>" +jsobject[i].position+ "</td>" + "<td><a herf= ' # ' onclick=" Edituser (tr "+i+"); " > Edit </a></td> "+ "</tr>"; } div.innerhtml=htmlstr+ "</table>"; } function Loading () { Div.style= "With:100%;text-align:center"; Div.innerhtml= "<font color=red> is fetching data please wait ... ...</font>"; }