I have two methods to read JSON in js: obj. name-based access, and array-based access. I will share with you the introduction and examples below.
Method 1: function construction definition method return
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Var strJSON = "{name: 'json name'}"; // obtain the json
Var obj = new Function ("return" + strJSON) (); // converted JSON object
Alert (obj. name); // json name |
Method 2: The famous eval function in js
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Var strJSON = "{name: 'json name'}"; // obtain the json
Var obj = eval ("(" + strJSON + ")"); // converted JSON object
Alert (obj. name); // json name |
Note that the object expression {'name': 'json name'} must be expanded with "()". Otherwise
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Var strJSON = "{name: 'json name '}";
Var obj = eval (strJSON );
Alert (obj. constructor); // String constructor
Alert (obj. name); // undefine |
You must extend the object expression to eval for execution to generate an anonymous object!
Example 1
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Var data = {name: "", age: "21", height: "189", gender: "male", weight: "60 KG "} For (var I in data ){ Console. log (I + ': "' + data [I] + '"'); } |
// Result: name: ""......
Example 2: ajax submits data and then returns json data processed by js
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<! Doctype html public "-// W3C // dtd html 4.01 Transitional // EN"> <Html>
<Head>
<Title> asynchronous JSON call </title>
</Head>
<Meta http-equiv = "Content-Type" content = "text/html; charset = UTF-8"/>
<Script type = "text/javascript">
<! --
Var xmlhttp;
// Create an XMLHTTPRequest object
Function createXMLHTTPRequest ()
{
If (window. ActiveXObject) // ② if the current browser is IE
{
Xmlhttp = new ActiveXObject ("Microsoft. XMLHTTP ");
}
Else if (window. XMLHTTPRequest) // ③ if it is another browser
{
Xmlhttp = new XMLHTTPRequest ();
}
}
Function getInfo ()
{
CreateXMLHTTPRequest ();
Xmlhttp. open ("get", "/webapp/front/dealerapi! Getdealerlist. action ", true );
Xmlhttp. onreadystatechange = returnInfo;
Xmlhttp. send (null );
}
Function returnInfo ()
{
If (xmlhttp. readyState = 4)
{
Var info = xmlhttp. responseText;
Eval ("var json =" + info );
Var message = "";
Var dealerlocation = "";
Var salesphone = "";
For (var I = 0; I <json. dealers. length; I ++ ){
Message + = "dealer name: <font style = 'color: red; '>" + json. dealers [I]. name + "</font> & nbsp; <br/> ";
Salesphone + = "dealer Phone: <font style = 'color: red; '>" + json. dealers [I]. salesphone + "</font> & nbsp; <br/> ";
Dealerlocation + = "dealer latitude and longitude: <font style = 'color: red; '>" + json. dealers [I]. location + "</font> & nbsp; <br/> ";
}
Document. getElementById ("showInfo"). innerHTML = message;
Document. getElementById ("salesphone"). innerHTML = salesphone
Document. getElementById ("location"). innerHTML = dealerlocation;
}
} -->
</Script>
<Body>
<Br/>
<H2 style = "color: red;"> asynchronous JSON call <Br/> <input type = "button" value = "retrieve JSON data" onclick = "getInfo ()"/>
<Table>
<Tr>
<Td> <div id = "showInfo"> </div> </td>
<Td> <span id = "salesphone"> <span> </td>
<Td> <span id = "location"> <span> </td>
</Tr>
</Table>
</Body>
</Html> |
