如何将PHP *变量*发送回jQuery而不回显？

I am using the ajax() function to send a string to a PHP file.

In case of a success, the PHP file echoes "the validation of the string was successful". But I would also like to send the actual string back to jQuery and put it in a div.

How can send back that string, without having to echo it along with the confirmation message?

Or should I put both messages into a string, send it to jQuery and have jQuery split that string? What's the best way?

Putting what others have said into code, you might set up your PHP script to return a JSON-encoded object like so:

$result = array(
  'message' => 'the validation of the string was successful',
  'original' => 'string sent by client'
);

echo json_encode($result);

On the client side, you can then access each piece from your callback function like so:

function (result) { 
  alert(result.message);
  // do something with result.original
}

I would return JSON with the string and the validation message.