How to get variable from the json response in javascript?

Question

I am facing problem in getting the variables from my response string. My response is like this:

responseText = {'page':'2','endOfPage':'yes','content':'abc'}

alert(responseText.page);

is returning undefined, can anyone suggest how to do it??

Answer 1

Your problem is that your responseText is in fact a string ( responseText = "{'page':'2','endOfPage':'yes','content':'abc'}"; ). You first have to parse it to create an object, this fails though because you are using single quotes, which are not valid JSON - you'll need to use double quotes for resolving the problem:

var json= "{ \"page\": 2, \"endOfPage\": \"yes\", \"content\": \"abc\" }";
var obj = JSON.parse(json);
alert(obj.page);

If you can't change the JSON-generator implementation to return a response with double quotes, try to replace every single quote into a double quote like this:

var invalidJson = "{'page':'2','endOfPage':'yes','content':'abc'}";
validJson= invalidJson.replace(/\'/g, "\"");
var obj = JSON.parse(validJson);
alert(obj.page);

Answer 2

• If you are using jQuery, you could use this :

responseText = '{"page":"2","endOfPage":"yes","content":"abc"}';
responseText = jQuery.parseJSON(responseText);
alert(responseText.endOfPage);

• In Javascript:

 responseText = '{"page":"2","endOfPage":"yes","content":"abc"}'; alert(JSON.parse(responseText).page); 

which is supported in some modern browsers for parsing JSON into a native js object

Answer 3

You need to use the eval function to convert json to object:

responseText = {'page':'2','endOfPage':'yes','content':'abc'}​​​​
var responseObject = eval(responseText);

alert(responseObject.page);