致命錯誤：調用未定義的函數在PHP

Question

我有PHP網站

if (isset($_POST['Confirm'])) { 

    $payment = $_SESSION['payment']; 
    $paymode = checkpaymentmode($payment); //get paymentmode code 
    $mtxcd = getmtxcd(); //merchant transaction code 


    if (!function_exists('checkpaymentmode')) { 
     function checkpaymentmode($payment) { 
      if ($payment == 'Amex') { 
       return "A"; 
      } elseif ($payment == 'Direc-Debit') { 
       return "D"; 
      } else { 
       return "C"; 
      } //assume the rest are visa/master 
     } 

    } 

} 

此代碼是第一部分確認頁面的支付部下面的代碼。確認後，執行這些代碼。在這個頁面中使用一些其他功能以及這個功能。我評論這一個，並嘗試與其他人，所有功能都有同樣的錯誤。

Fatal error: Call to undefined function checkpaymentmode() in line33..

任何解決方案??

Answer 1

要調用的定義之前的函數

$paymode = checkpaymentmode($payment); //get paymentmode code 

。

添加功能的函數被調用像以前一樣，

if (!function_exists('checkpaymentmode')) { // define the fucntion 
     function checkpaymentmode($payment) { 
      if ($payment == 'Amex') { 
       return "A"; 
      } elseif ($payment == 'Direc-Debit') { 
       return "D"; 
      } else { 
       return "C"; 
      } //assume the rest are visa/master 
     } 

    } 

if (isset($_POST['Confirm'])) { 

    $payment = $_SESSION['payment']; 
    $paymode = checkpaymentmode($payment); //get paymentmode code 
    $mtxcd = getmtxcd(); //merchant transaction code 
    -------------------------- 
} 

Answer 2

你打電話定義之前的功能，您需要將您的IF子句定義函數頂端，同樣

if (isset($_POST['Confirm'])) { 
    if (!function_exists('checkpaymentmode')) { 
     function checkpaymentmode($payment) { 
      if ($payment == 'Amex') { 
       return "A"; 
      } elseif ($payment == 'Direc-Debit') { 
       return "D"; 
      } else { 
       return "C"; 
      } //assume the rest are visa/master 
     } 

    } 

    $payment = $_SESSION['payment']; 
    $paymode = checkpaymentmode($payment); //get paymentmode code 
    $mtxcd = getmtxcd(); //merchant transaction code 

} 

Answer 3

您在實現它之前調用該函數。移位這些代碼

$payment = $_SESSION['payment']; 
    $paymode = checkpaymentmode($payment); //get paymentmode code 
    $mtxcd = getmtxcd(); //merchant transaction code 

下面的功能，它應該工作。