PHP中include和require的区别实例分析

　　先编辑command.php文件

　　 echo hello.PHP_EOL;

　　然后编辑console.php文件

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

　　原本想要包含并执行这个echo，没想到写错了文件名，如果是require，会报出这样的错误：

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

　　如果把require改为include

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

　　会报出这样的错误：

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

　　如果使用require_once或者include_once，只要包含路径正确，那么循环只执行一次。

　　总结：

　　使用require，如果文件没有包含成功，就会报出一个fatal error，整个程序就中止了。

　　使用include，如果文件没有包含成功，就会报出一个普通的warning，之后的代码仍会执行。

　　如果你的Web程序使用了MVC这种对文件包含强依赖的设计方法，请使用require_once。