PHP中有什么例外，什么是try和catch？ [英] What is an exception in PHP for and what is try and catch?

问题描述

我在PHP中使用对象/类很新，我很好奇 EXCEPTIONS ， TRY 和 CATCH

I am pretty new to using object/classes in PHP and I am curious about EXCEPTIONS, TRY, and CATCH

在下面的示例中，我使用了所有3。显然一个例外是触发错误的某种方式，但我不明白为什么？在下面的代码中，我可以很容易地显示某种错误或者没有异常的东西？

In the example below I have all 3 shown in use. Obviously an exception is some sort of way of triggering an error but I do not understand why? In the code below I could easily show some sort of error or something without the exception part there?

下面的例子是一个使用try和catch的例子。在我看来，与if / else一样。我可能是错的，这只是我看到他们的方式，而不知道什么，我意识到你可以在PHP中编写任何东西，而不使用这些，所以什么原因，有什么利益比使用这些东西与传统的方式？ >

Below that example is an example using try and catch. It appears to me to be the same as using if/else. I may be wrong, this is just the way I see them without knowing anything, I realize you can code anything in PHP without using these so what is the reason, is there any benefit over using this stuff vs the traditional ways?

<?PHP
// sample of using an exception
if($something === $something_else){
    //do stuff
}else if($something === $something_else_again){
    //do stuff
}else{
    throw new Exception('Something went wrong!');
}

尝试捕捉

//and try and catch
try{
    $thumb = PhpThumbFactory::create('/path/to/image.jpg');
}
catch (Exception $e){
    // handle error here however you'd like
}
?>

推荐答案

为了简短起见，一个例外是 em>特殊情况，改变程序执行的正常流程（引用维基百科）

To make things short, an exception is a "special condition that change the normal flow of program execution" (quoting wikipedia)

您可能对（至少）这几篇文章感兴趣：

You might be interested by (at least) those couple of articles :

• 异常处理 - 维基百科


• 异常PHP：异常介绍


• 异常PHP：扩展基础异常类


• 卓越的PHP：在PHP中嵌套异常

• Exception handling - wikipedia
• Exceptional PHP: Introduction to Exceptions
• Exceptional PHP: Extending The Base Exception Class
• Exceptional PHP: Nesting Exceptions In PHP

他们应该给你我有趣的元素 - 特别是第二个，php中有什么例外

They should give you some interesting elements -- especially the second one, for "what is an exception in php"

优点之一是基本思想的一部分）是：

• 您在中有正常代码尝试块


• ，处理问题代码的最大部分是在 catch 块


• 这意味着在正常代码


• 中间更少的处理问题代码，并且还允许您重新组合处理问题代码部分

• you have the "normal" code in the try block
• and the biggest part of the "dealing with problems" code is in the catch block
• which means less "dealing with problems" code in the middle of the "normal" code
• and also allows you to regroup "dealing with problems" portions of code

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