PHP中include和require的区别实例分析
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2024-03-08 23:41:52
先编辑command.php文件
echo 'hello'.php_eol;
然后编辑console.php文件
for($i=1;$i<...
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。
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