$data = array( 'name' => 'John Doe', 'age' => 30, 'email' => 'john.doe@example.com' ); header('Content-Type: application/json'); echoJson($data);In this example, we create an array of data that we want to send back to the client. We then set the content type header to `application/json` to tell the client that we are sending JSON data. Finally, we call `echoJson` with the data array as its argument, which will send the data back to the client as a JSON response. echoJson is typically included in a package or library for building RESTful APIs in PHP, such as Slim Framework or Laravel.