Question

我正在尝试调试一些代码。我希望能够在try中显示catch中定义的变量。例如变量$siteId。

<?php
try {
    $siteId = 3;
    if(1 !== 2) {
        throw new Exception('1 does not equal 2!');
    }
} catch(Exception $e) {
    $moreInfo = '';
    if(isset($siteId)) {
        $moreInfo .= ' SiteId»' . $siteId;
    }
    echo 'Error' . $moreInfo . ':' . $e->getMessage();
}
?>

我得到的回复是Error: 1 does not equal 2!，而不是Error SiteId»3: 1 does not equal 2!。我做错了什么？

Answer 1

在try / catch构造之外声明$ siteId并在catch中使用!empty($siteId)。

$siteId = null;
try {

}catch(Exceptions $e) {
  if( ! empty($siteId) ) {

  }
}

Answer 2

PHP中的变量的范围是文件，方法或函数，（参见http://php.net/manual/en/language.variables.scope.php），所以我不确定这对你不起作用。快速切入PhpStorm可以为我输出正确的响应。

Answer 3

尝试将\添加到Exception课程。所以你的代码变成了：

<?php
try {
    $siteId = 3;
    if(1 !== 2) {
        throw new \Exception('1 does not equal 2!');
    }
} catch(\Exception $e) {
    $moreInfo = '';
    if(isset($siteId)) {
        $moreInfo .= ' SiteId»' . $siteId;
    }
    echo 'Error' . $moreInfo . ':' . $e->getMessage();
}
?>

Answer 4

尝试从try / catch移出$ siteId：

<?php
$siteId = 3;
try {        
    if(1 !== 2) {
        throw new Exception('1 does not equal 2!');
    }
} catch(Exception $e) {
    $moreInfo = '';
    if(isset($siteId)) {
        $moreInfo .= ' SiteId»' . $siteId;
    }
    echo 'Error' . $moreInfo . ':' . $e->getMessage();
}
?>

Answer 5

我正在使用PHP 7.2，在我的情况下，在catch块中定义的变量在catch中不可用，所以这是一个解决方法：

protected $var;

try  {

 $var = 'Hello World';

 // Saving var in an external variable so it can be accessed by Catch
 $this->var = $var;

 throw new Exception("Error Processing Request", 1);

} catch (Exception $e) {

   var_dump($var); // null
   var_dump($this->var); // 'Hello World'

}

Answer 6

<?php
$siteId = 3;
try {

    if(1 !== 2) {
        throw new Exception('1 does not equal 2!');
    }
} catch(Exception $e) {
    $moreInfo = '';
    if(!empty($siteId)) {
        $moreInfo .= ' SiteId»' . $siteId;
    }
    echo 'Error' . $moreInfo . ':' . $e->getMessage();
}
?>

Answer 7

我在php7中遇到了同样的问题，并且以某种方式对我有用

class dbConfig {
    private $servername ; private $username; private $password; private $conn;

     public function __construct()
    {
        $this->connect();
    }
    public function connect()
    {
        $servername = 'localhost';
        $username = 'root';
        $password= '';
        $dbName = 'dbname';
        try {
            $conn = new PDO("mysql:host=$servername;dbname=$dbName", $username, $password);
            // set the PDO error mode to exception
            $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
            echo "Connected successfully"; 
            }
        catch(PDOException $e)
            {
            echo "Connection failed: " . $e->getMessage();
            }
    }

PHP try catch：在try中定义变量

7 个答案: