致命错误：调用未定义的函数在PHP

Question

我有PHP网站

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 
     } 

    } 

} 

此代码是第一部分确认页面的支付部下面的代码。确认后，执行这些代码。在这个页面中使用一些其他功能以及这个功能。我评论这一个，并尝试与其他人，所有功能都有同样的错误。

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

任何解决方案??

Answer 1

要调用的定义之前的函数

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

。

添加功能的函数被调用像以前一样，

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

你打电话定义之前的功能，您需要将您的IF子句定义函数顶端，同样

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

您在实现它之前调用该函数。移位这些代码

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

下面的功能，它应该工作。