使用Ajax帖子(有点困惑）

我正在使用wordpress插件中的ajax帖子来提交和验证表单值。这是我第一次使用ajax，对它的工作原理有点困惑。这是我的ajax帖子：

           jQuery.ajax({
                type:"post",
                dataType:"json",
                url: myAjax.ajaxurl,
                data: {action: 'submit_data', info: info},
                success: function(response) {
                    if (response.type == "success") {
                        alert("success");
                    }
                    else {
                        alert("fail");
                    }
                }
            });

这会将数据发布到名为 submit_data 的 php 函数，如下所示：

function submit_data() {
    $nameErr = $emailErr = $phoneErr = $commentErr = "";
    $full = explode("&", $_POST["info"]);
    $fname = explode(":", $full[0]);
    $name = $fname[1];
    $femail = explode(":", $full[1]);
    $email = $femail[1];
    $fphone = explode(":", $full[2]);
    $phone = $fphone[1];
    $fcomment = explode(":", $full[3]);
    $comment = $fcomment[1];
    if ((empty($name)) || (strlen($name) < 4)){
        $nameErr = "Please enter a name";
    }
    else if (!preg_match("/^[a-zA-Z ]*$/", $name)) {
        $nameErr = "Please ensure you have entered your name and surname";
    }

    if (empty($email)) {
        $emailErr = "Please enter an email address";
    }
    else if (!preg_match("/(['w'-]+'@['w'-]+'.['w'-]+)/", $email)) {
        $emailErr = "Please ensure you have entered a valid email address";
    }

    if (empty($phone)) {
        $phoneErr = "Please enter a phone number";
    }
    else if (!preg_match("/(?:'(?'+'d{2}')?'s*)?'d+(?:[ -]*'d+)*$/",$phone)) {
        $phoneErr = "Please ensure you have entered a valid phone number";
    }

    if ((empty($nameErr)) && (empty($emailErr)) && (empty($phoneErr)) && (empty($commentErr))) {
        $conn = mysqli_connect("localhost", "Mikey", "Change0", "plugindatadb");
        mysqli_query($conn, "INSERT INTO data (Name, Email, Phone, Comment) VALUES ('$name', '$email', '$phone', '$comment')");
    }
    else {
        $errorArray = array();
        if (!empty($nameErr)) {
            $errorArray["nameErr"] = $nameErr;
        }
        if (!empty($emailErr)) {
            $errorArray["emailErr"] = $emailErr;
        }
        if (!empty($phoneErr)) {
            $errorArray["phoneErr"] = $phoneErr;
        }
        if (!empty($commentErr)) {
            $errorArray["commentErr"] = $commentErr;
        }
    }
    die();
}

我的问题是，如果 submit_data 函数成功运行而没有错误，那么代码是否运行 ajax 成功函数？还是 ajax 成功函数在遇到submit_data结束之前运行？