php - 嵌套的 try catch 在 PHP 中

Question

考虑:

try{
    class MyException extends Exception{}
    try{
        throw new MyException;
    }
    catch(Exception $e){
        echo "1:";
        throw $e;
    }
    catch(MyException $e){
        echo "2:";
        throw $e;
    }
}
catch(Exception $e){
    echo get_class($e);
}

我对这个 try and catch 很困惑。由于第二个 try throw MyException，我期待 2:MyException 结果。但实际结果是1:MyException。什么解释？

Answer 1

MyException extends Exception，所以Exception比MyException更通用，第一个catch block 将捕获它。如果你想捕获 MyException，你需要颠倒 catch block 的顺序:

class MyException extends Exception{}

try {
 try {
   throw new MyException;
 } catch(MyException $e){
   echo "2:";
   throw $e;
 } catch(Exception $e){
   echo "1:";
   throw $e;
 }
}catch(Exception $e){
echo get_class($e);
}