在PHP中检索AJAX数据

Question

I need to use the xhr.send(VALUE) to send the data in AJAX. How do I get this data in a PHP file?

JS:

window.onload = function() {
    var value = 'hello';
    var xhr = new XMLHttpRequest();
    xhr.onreadystatechange = function() {
        if(xhr.readyState == 4 && xhr.status == 200) {
            alert(xhr.responseText);
        } else {
            alert("no");
        }
    }
    xhr.open('POST', 'json.php', true);
    xhr.send(value);

}

Answer 1

If you want to see the $_POST variables on the PHP page you can use this code to display them all so you can visually see their keys and values

echo "<pre>";
print_r($_POST);
echo "</pre>";

From there you will know how to use the data in any file. You can do the same thing with $_GET