Question

我对一些if / else语句进行了验证。

<?php
if (isset($_POST["join"])) { 

  if ($userpoint < $lessonpoint) { //pt
    echo "you need more points";
  } //pt

  else { //has enough point


      if ($row['num'] > 0) { //check if user took this lesson
        echo "you took this lesson before.";
      } //check if user took this lesson ends


    else { //then let him apply to database

            //define post:
            $postvalue = (int)$_POST["postvalue"];

            //and check
            if($postvalue == '' || $postvalue <= 0 || $postvalue > $minimumpostvalue || $postvalue == is_int($postvalue)) { //check post
            echo "Error."; 

            } //checkpost ends.


      else { //insert

      $sql = "INSERT into etc... VALUES (?, ?, ?)";

            if($sql){ //to another database

                $artibir = "UPDATE etc.";

                echo "Done.";

            } // to another database
      }//insert
    } //let him apply
  } //has enough point
} //if post isset join
?>

这非常有效。

但我想回应一下这个条件的另一条错误消息：$postvalue > $minimumpostvalue

尝试时，我迷失在if / else语句中。无论我把新陈述放在哪里我都有错误。

定义了所有变量。

我在哪里以及如何放置$postvalue > $minimumpostvalue来回显不同的错误消息？

Answer 1

<?php
if (isset($_POST["join"])) {

   if ($userpoint < $lessonpoint) { //pt
     echo "you need more points";
   } //pt

    else { //has enough point

         if ($row['num'] > 0) { //check if user took this lesson
             echo "you took this lesson before.";
         } //check if user took this lesson ends

        else { //then let him apply to database

             //define post:
             $postvalue = (int) $_POST["postvalue"];

             //and check
                  if ($postvalue == '' || $postvalue <= 0 || $postvalue > $minimumpostvalue || $postvalue == is_int($postvalue)) { //check post
                        if ($postvalue > $minimumpostvalue) {
                            echo "Another Error.";
                         } 
                        else {
                           echo "Error.";
                         }

                   } //checkpost ends.

                  else { //insert

                       $sql = "INSERT into etc... VALUES (?, ?, ?)";

                       if ($sql) { //to another database

                           $artibir = "UPDATE etc.";

                           echo "Done.";

                       } // to another database
                  } //insert
              } //let him apply
     } //has enough point
} //if post isset join
?>

Answer 2

这是另一种例外情况。

只要$ valid变为false，它就会跳过下一次验证。

<?php
$valid = true;
$error = '';

if ($valid && !isset($_POST["join"])) {
    $error = 'Not a join post request';
    $valid = false;
}

if ($valid && ($userpoint < $lessonpoint)) {
    $error = 'You need more points';
    $valid = false;
}

...

if($valid) {
    // Database insert; redirect
} else {
    // User error feedback
}

Answer 3

//and check
if ($postvalue > $minimumpostvalue) { //check exception
   echo "Error 1."; 
} elseif ($postvalue == '' || $postvalue <= 0 || $postvalue == is_int($postvalue)) { //check the rest
      echo "Error 2."; 
} //checkpost ends.

Answer 4

这是未经测试的代码，更多是如何避免嵌套if语句的示例。

关键是要尽早说明你有错误状态的条件，并尽快退出，最好是抛出异常并避免else语句。

为简单起见，我只使用了\RunTimeException()，但我很可能根据具体情况定义自己的异常。然后可以捕获异常，并根据其类型显示不同的错误页面。

/**
 * @param int $postvalue
 * @param int $minimumpostvalue
 */
function saveToDatabase($postvalue)
{
    if ($postvalue == '' || $postvalue <= 0 || $postvalue == is_int($postvalue)) {
        throw new \RuntimeException('Error 2');
    }

    $sql = "INSERT into etc... VALUES (?, ?, ?)";
    if ($sql) {
        $artibir = "UPDATE etc.";
    }
}

if (!isset($_POST["join"])) {
    throw new \RuntimeException('Not a join post request');
}

if ($userpoint < $lessonpoint) {
    throw new \RuntimeException('You need more points');
}

$userHasTakenCourse = $row['num'] > 0;
if ($userHasTakenCourse) {
    throw new \RuntimeException('User has already taken the course.');
}

$postvalue = (int) $_POST["postvalue"];
if ($postvalue > $minimumpostvalue) {
    throw new \RuntimeException('Error 1');
}

saveToDatabase($postvalue);

如何拆分if else错误条件

4 个答案: