Preface

Among the changes in PHP7, those that have a greater impact include Exception handling.

Overview

More exceptions are handled directly through PHP. Different from the previous PHP5, more exceptions are thrown through Error exceptions.

As a normal extension, Error exceptions will continue to pop up until the corresponding catch block is matched. If no match is made, the set set_exception_handler() will be triggered to perform processing. If there is no default exception handler, the exception will be converted to a fatal error and will be treated like a traditional The error is handled.

Since Error does not inherit exceptions in the error hierarchy, code like this catch (Exception $e) { ... } will not catch the corresponding exception in PHP5. We can use the code catch (Error $e) { ... } or set_exception_handler() to handle Error.

Wrong hierarchy

Throwable

##….
ArithmeticError Arithmetic Error
AssertionError Statement Error
ParseError Parse Error
TypeError Type error
pisionByZeroError Divisor by 0 error
Error Error
Exception Exception

PHP RFC

Throwable Interface

function add(int $left, int $right) {
    return $left + $right;
}try {    echo add(&#39;left&#39;, &#39;right&#39;);
} catch (Exception $e) {    // Handle exception} catch (Error $e) { // Clearly a different type of object
    // Log error and end gracefully
    var_dump($e);
}

Copy after login

Here, there is no server 500 error. The reason is that the Error in PHP7 intercepts it and does not bubble up in the server.

object(TypeError)#1 (7) {
  ["message":protected]=>  
  string(139) "Argument 1 passed to add() must be of the type integer, string given, called in /Applications/mamp/apache2/htdocs/curl/error.php on line 14"
  ["string":"Error":private]=>  string(0) ""
  ["code":protected]=>  int(0)
  ["file":protected]=>  string(48) "/Applications/mamp/apache2/htdocs/curl/error.php"
  ["line":protected]=>  int(9)
  ["trace":"Error":private]=>
  array(1) {
    [0]=>
    array(4) {
      ["file"]=>      string(48) "/Applications/mamp/apache2/htdocs/curl/error.php"
      ["line"]=>      int(14)
      ["function"]=>      string(3) "add"
      ["args"]=>
      array(2) {
        [0]=>        string(4) "left"
        [1]=>        string(5) "right"
      }
    }
  }
  ["previous":"Error":private]=>
  NULL
}

Copy after login

So we can record them through logs.

Exceptions in the engine (for PHP 7)

function call_method($obj) {
    $obj->method();
}try {
    call_method(null);
     // oops!
     } 
     catch (EngineException $e) {    
    echo "Exception: {$e->getMessage()}\n";
}//其实上面的例子我在运行过程中，并没有被EngineException捕获异常,经过测试，也是通过Error进行的错误的拦截

Copy after login

If the exception is not caught, PHP will continue to throw the same fatal error as it currently does.

Reclassify E_STRICT notices

The above is the detailed content of Detailed introduction to exception handling code examples in PHP7. For more information, please follow other related articles on the PHP Chinese website!