Error handling and exception handling in PHP

This article mainly introduces error handling and exception handling in PHP. Interested friends can refer to it. I hope it will be helpful to everyone.

Error handling:
    
  1. Syntax error
  2. Runtime error
  3. Logic error

Error report:
                                                                                                                                                          #Development phase: Output all error reports during development, which is helpful for us to debug

Running phase: Do not let the program output any kind of error report

Write the error report to the log Medium

1. Specify error reporting error_reporting=E_ALL (in php.inn)

2. Turn off error output display_errors=off (in php.ini)

3. Turn on the error log function log_errors=on (in php.ini)

1. By default, if the error log location is not specified, it will be written to the log of the web server by default. 2. Specify a file name for the error_log option. This file name is the error. Log3. Write to the operating system log error_log=syslog

<?php
//注意和警告都不会终止程序的运行，但是错误会终止程序的运行

/*
错误E_ERROR
警告E_WARNING
注意E_NOTICE
*/
//所有的错误都输出除了注意
error_reporting(E_ALL & ~E_NOTICE);

//设置配置文件的值（临时）
//ini_set("upload_max_filesize", 2000000000);

//得到配置文件的值
//ini_get("upload_max_filesize");

//关闭错误报告的显示，一般在运行阶段使用
ini_set("display_errors", "off");
//将错误报告写入日志中
ini_set("log_errors", "on");
//日志的目录
ini_set("error_log", "D:/error.log");
gettype($var);  //注意

gettype();    //警告

//getype();    //错误，程序终止

echo "############<br>";
?>

Exception handling:

Accidents are unexpected things that happen during the running of the program. Use exceptions to change the normal flow of the script

A new important thing in PHP5 Features

try{ }catch(Exception object){

}

1. If the code in try If there is no problem, then after the execution of the code in try is completed, go to the catch and execute

2. If an exception occurs in the code in try, an exception object (using throw) will be thrown to the catch. parameters, the content after the exception code appears in the try will not be executed, and it will jump directly to the catch for execution. After the execution is completed in the catch, continue to execute downwards

<?php
try{
  echo "11111111<br>";
  $file=@fopen("./hello.txt","r");
  if(!$file){
    throw new Exception("文件打开失败");
    
  }
  echo "2222222222<br>";
}catch(Exception $e){
  echo "3333333<br>";
  echo $e->getMessage()."<br>";
  touch("hello.txt");
  $file=@fopen("./hello.txt","r");
}
echo "4444444<br>";
?>

The above is the entire content of this article, I hope it will be helpful to everyone's study.

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##Exception
and error parsing

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##PHP implementationExceptionMethods for handling classes

php encapsulates a ExceptionMethods for handling classes

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