Answers for "how to return json data without echo php"

php echo json

<?php
$data = ['name' => 'John', 'age' => 35];
header('Content-type: Application/json');
echo json_encode($data);

php return a json response

//PHP File
<?php
$data = /** whatever your data are **/;
header('Content-Type: application/json; charset=utf-8');
echo json_encode($data);

//In JS File
//JQUERY AJAX
        $.ajax({
        url: "path/to_php_file.php",
        dataType: "json",  
        type: "GET",
        data: {datax : datax },