parsing JSON using javascript gives me undefined while getting the value from the json response

i am parsing an json string usin javascript

    {
      "head":   {
        "example": "0"
         },
      "res":   {
        "@test": "121",
        "@found": "5"
     }
}

i am getting the http response from the remote site and i am using javascript to extract the @found value .i used the below code .

 var json=eval('('+request.responseText+')');
        alert(json.head.res.@found);

gives me a null value c开发者_如何学Goan u please tell me how can i parse this.

alert(json.head.res['@found']);

@ is not valid to start a variable name, so you have to use bracket notation. Or change the variable name to be valid.

Basically, in regular expression form: [a-zA-Z_$][0-9a-zA-Z_$]*. In other words, the first character can be a letter or _ or $, and the other characters can be letters or _ or $ or numbers.

What characters are valid for JavaScript variable names?

Attribute "res" is not inside "head" attribute.

Try this: json.res['@found']

Try json.res['@found']. JavaScript object properties that are not valid variable names cannot be accessed using dot notation. Also, as noted by others, @found is not in head.

fix these 3 things :

• @ is not a valid variable name character. you should consider the [] syntax instead of the "dot" one.
• res is not in head.
• please don't use eval. I strongly advise you to use JSON.parse instead of eval

var json = JSON.parse(request.responseText);
alert(json.res['@found']);

alert(json.res['@found']);

res is not inside head.