JSON stands for javascript object notation (as I'm sure you're aware), so why, when sending json via ajax do you need to turn it into a string to send it? Is it simply a formatting thing, or what?

This may belong in another place, if so, let me know, I'll close it and move it.

Obviously, I'm not looking for opinions, I'd like to know the actual answer.

Just to make sure I'm clear, I understand what JSON.stringify() does, and its counterpart JSON.parse(). I just want to know, why using stringify is required.

Thanks!

JSON stands for javascript object notation (as I'm sure you're aware), so why, when sending json via ajax do you need to turn it into a string to send it? Is it simply a formatting thing, or what?

This may belong in another place, if so, let me know, I'll close it and move it.

Obviously, I'm not looking for opinions, I'd like to know the actual answer.

Just to make sure I'm clear, I understand what JSON.stringify() does, and its counterpart JSON.parse(). I just want to know, why using stringify is required.

Thanks!

• javascript
• json
• ajax

• 5 The reason is: HTTP only knows plain text! Ajax itself is agnostic for special data types, it can be used to send and receive arbitrary data types, which are transmitted as plain text data in the HTTP body. So if JSON is wanted, the text from the HTTP level has to be converted from/to the JSON data format somewhere. – rplantiko Commented Sep 14, 2015 at 17:33
• What exactly would it mean to send a raw JavaScript object in an HTTP request? – Pointy Commented Sep 14, 2015 at 17:34
• JSON is a string representation of data, similar to XML. Stringify converts JavaScript objects (and arrays) into this string format. – gen_Eric Commented Sep 14, 2015 at 17:35

3 Answers 3

when sending json via ajax do you need to turn it into a string to send it?

If it isn't a string, then it isn't JSON in the first place.

JSON is a text based data format. HTTP is a text based communications protocol.

JSON stands for javascript object notation

JSON is based on the syntax for JavaScript literals. A JavaScript object is not JSON.

AJAX is all about HTTP requests, which are basically "text" requests to a server. That's the main reason why you have to stringify your object: That way it's turned into text that can "travel" over HTTP.

When sending data to a web server, the data has to be a string.

That's why we are using JSON.stringify() function to convert data to string and send it via XHR request to the server.

        // Creating a XHR object 
        let xhr = new XMLHttpRequest();
        let url = "submit.php"; 

        // open a connection 
        xhr.open("POST", url, true); 

        // Set the request header i.e. which type of content you are sending 
        xhr.setRequestHeader("Content-Type", "application/json"); 

        // Converting JSON data to string 
        var data = JSON.stringify({ "name": name.value, "email": email.value }); 

        // Sending data with the request 
        xhr.send(data);