Difference between include and require in PHP instance analysis and require instance analysis

Difference between include and require in PHP instance analysis and require instance analysis

Edit the command. php file first

echo 'hello'.PHP_EOL;

Edit the console. php file.

for($i=1;$i<=3;++$i){require 'command1.php';}

I originally wanted to include and execute this echo. I did not expect to write the wrong file name. If it is require, this error will be reported:

Warning: require(command1.php): failed to open stream: No such file or directory in console.php on line 4Fatal error: require(): Failed opening required 'command1.php' (include_path='.') in console.php on line 4PHP Warning: require(command1.php): failed to open stream: No such file or directory in console.php on line 4PHP Fatal error: require(): Failed opening required 'command1.php' (include_path='.') in console.php on line 4

If you change require to include

for($i=1;$i<=3;++$i){include 'command1.php';}

The following error is reported:

Warning: include(command1.php): failed to open stream: No such file or directory in console.php on line 4Warning: include(): Failed opening 'command1.php' for inclusion (include_path='.') in console.php on line 4Warning: include(command1.php): failed to open stream: No such file or directory in console.php on line 4Warning: include(): Failed opening 'command1.php' for inclusion (include_path='.') in console.php on line 4Warning: include(command1.php): failed to open stream: No such file or directory in console.php on line 4Warning: include(): Failed opening 'command1.php' for inclusion (include_path='.') in console.php on line 4PHP Warning: include(command1.php): failed to open stream: No such file or directory in console.php on line 4PHP Warning: include(): Failed opening 'command1.php' for inclusion (include_path='.') in console.php on line 4PHP Warning: include(command1.php): failed to open stream: No such file or directory in console.php on line 4PHP Warning: include(): Failed opening 'command1.php' for inclusion (include_path='.') in console.php on line 4PHP Warning: include(command1.php): failed to open stream: No such file or directory in console.php on line 4PHP Warning: include(): Failed opening 'command1.php' for inclusion (include_path='.') in console.php on line 4

If require_once or include_once is used, the loop is executed only once if the inclusion path is correct.

Summary:

If require is used, if the file is not included successfully, a fatal error is reported, and the entire program is aborted.

Use include. If the file is not successfully included, a normal warning will be reported and subsequent code will still be executed.

Use require_once if your Web application uses the MVC design method that is highly dependent on files.