失敗消息未出現在表單驗證事件中

Question

我試圖製作一個失敗消息，它根據提交時的錯誤將不同的字符串加在一起。但是，即使條件滿足，失敗消息也不會出現。 我想知道我的代碼中的錯誤在哪裏。謝謝。

這是在鏈接到HTML文檔的外部JavaScript文件中。

function validationEvent() { 
    var flag = true; 
    var alertmsg = "There were errors found in your registration:"; 
    var givenname = document.getElementById("gname").value; 
    var surname = document.getElementById("sname").value; 
    var address = document.getElementById("address1").value; 
    var city = document.getElementById("city").value; 
    var pcode = document.getElementById("pcode").value; 
    var email = document.getElementById("email").value; 
    var phone = document.getElementById("phone").value; 
    var cnum = document.getElementById("cnum").value; 
    if (givenname == null || givenname == "") { 
     alertmsg += " Given Name is a mandatory field."; 
     flag = false; 

    } 
    if (surname == null || surname == "") { 
     alertmsg += " Surname is a mandatory field."; 
     flag = false; 

    } 
    if (address == null || address == "") { 
     alertmsg += " Address is a mandatory field."; 
     flag = false; 
     } 
    if (city == null || city == "") { 
     alertmsg += " City is a mandatory field."; 
     flag = false; 
     } 
    if (pcode == null || pcode == "") { 
     alertmsg += " Postal Code is a mandatory field."; 
     flag = false; 
     } 
    if (email == null || email == "") { 
     alertmsg += " Email is a mandatory field."; 
     flag = false; 
     } 
    if (phone == null || phone == "") { 
     alertmsg += " Phone Number is a mandatory field."; 
     flag = false; 
     } 
    if (cnum == null || cnum == "") { 
     alertmsg += " Credit Card Number is a mandatory field."; 
     flag = false; 
      } 
    if (!vormCredit()) { 
     alertmsg += " Visa Cards must start with 4 and Mastercard Cards must start with 5."; 
     flag = false; 

    } 
    if (!stateCheck()) { 
     alertmsg += " Invalid Postal Code."; 
     flag = false; 

    } 
    if (!checkCredit()) { 
     alertmsg += " Invaid Credit Card Number."; 
     flag = false; 

    } 
    if (!flag) { 
     alert(alertmsg); 
     return false;} 

    else { 
     alert("Thank you for your subcription."); 
     return true;} 


    }; 

編輯：從'if'循環中刪除'return false'，並將其僅添加到if（！標誌）循環中。

Answer 1

這裏最好使用switch聲明。它處理的情況下，當你有更多的案件。您也可以使用break。