错误和异常

在编码的时候，我们无时无刻会遇到错误和异常，所以我们需要处理这些错误。

php的错误类型有

• E_ERROR 致命的错误。会中断程序的执行
• E_WARNING 警告。不会中断程序
• E_NOTICE 通知，运行时通知。表示脚本遇到可能会表现为错误的情况
• E_PARSE 解析错误，一般是语法错误。
• E_STRICT PHP 对代码的修改建议
• E_DEPRECATED 将会对在未来版本中可能无法正常工作的代码给出警告

错误

在开发模式中，我们一般需要打开error_reporting 设置为E_ALL。然后把display_errors 设置为on

如果需要记录错误日志，则需要配置log_errors.

开发者可以 通过set_error_handle()自己接管错误。

set_error_handle(function($errno,$errstr,$errfile,$errline){
  
})
  
/**
* throw exceptions based on E_* error types
*/
set_error_handler(function ($err_severity, $err_msg, $err_file, $err_line, array $err_context)
{
    // error was suppressed with the @-operator
    if (0 === error_reporting()) { return false;}
    switch($err_severity)
    {
        case E_ERROR:               throw new ErrorException            ($err_msg, 0, $err_severity, $err_file, $err_line);
        case E_WARNING:             throw new WarningException          ($err_msg, 0, $err_severity, $err_file, $err_line);
        case E_PARSE:               throw new ParseException            ($err_msg, 0, $err_severity, $err_file, $err_line);
        case E_NOTICE:              throw new NoticeException           ($err_msg, 0, $err_severity, $err_file, $err_line);
        case E_CORE_ERROR:          throw new CoreErrorException        ($err_msg, 0, $err_severity, $err_file, $err_line);
        case E_CORE_WARNING:        throw new CoreWarningException      ($err_msg, 0, $err_severity, $err_file, $err_line);
        case E_COMPILE_ERROR:       throw new CompileErrorException     ($err_msg, 0, $err_severity, $err_file, $err_line);
        case E_COMPILE_WARNING:     throw new CoreWarningException      ($err_msg, 0, $err_severity, $err_file, $err_line);
        case E_USER_ERROR:          throw new UserErrorException        ($err_msg, 0, $err_severity, $err_file, $err_line);
        case E_USER_WARNING:        throw new UserWarningException      ($err_msg, 0, $err_severity, $err_file, $err_line);
        case E_USER_NOTICE:         throw new UserNoticeException       ($err_msg, 0, $err_severity, $err_file, $err_line);
        case E_STRICT:              throw new StrictException           ($err_msg, 0, $err_severity, $err_file, $err_line);
        case E_RECOVERABLE_ERROR:   throw new RecoverableErrorException ($err_msg, 0, $err_severity, $err_file, $err_line);
        case E_DEPRECATED:          throw new DeprecatedException       ($err_msg, 0, $err_severity, $err_file, $err_line);
        case E_USER_DEPRECATED:     throw new UserDeprecatedException   ($err_msg, 0, $err_severity, $err_file, $err_line);
    }
});

class WarningException              extends ErrorException {}
class ParseException                extends ErrorException {}
class NoticeException               extends ErrorException {}
class CoreErrorException            extends ErrorException {}
class CoreWarningException          extends ErrorException {}
class CompileErrorException         extends ErrorException {}
class CompileWarningException       extends ErrorException {}
class UserErrorException            extends ErrorException {}
class UserWarningException          extends ErrorException {}
class UserNoticeException           extends ErrorException {}
class StrictException               extends ErrorException {}
class RecoverableErrorException     extends ErrorException {}
class DeprecatedException           extends ErrorException {}
class UserDeprecatedException       extends ErrorException {}

PHP7的错误处理

PHP 7 改变了大多数错误的报告方式。error可以通过exception异常进行捕获到.不能通过try catch捕获。但是可以通过注册到set_exception_handle捕获。

• Throwable
  • Error
  • Exception

try
{
   // Code that may throw an Exception or Error.
}
catch (Throwable $t)
{
   // Executed only in PHP 7, will not match in PHP 5
}
catch (Exception $e)
{
   // Executed only in PHP 5, will not be reached in PHP 7
}

异常

捕获异常可以通过try catch 语句

try{
  //异常的代码
}catch (Exception $e){
  //处理异常
}finally{
  //最后执行的
}