先編輯command.php文件
echo 'hello'.PHP_EOL;
然后編輯console.php文件
for($i=1;$i<=3;++$i){ require 'command1.php';}原本想要包含并執(zhí)行這個(gè)echo，沒(méi)想到寫(xiě)錯(cuò)了文件名，如果是require，會(huì)報(bào)出這樣的錯(cuò)誤：
Warning: require(command1.php): failed to open stream: No such file or directory in console.php on line 4Fatal error: require(): Failed opening required 'command1.php' (include_path='.') in console.php on line 4PHP Warning: require(command1.php): failed to open stream: No such file or directory in console.php on line 4PHP Fatal error: require(): Failed opening required 'command1.php' (include_path='.') in console.php on line 4
如果把require改為include
for($i=1;$i<=3;++$i){ include 'command1.php';}會(huì)報(bào)出這樣的錯(cuò)誤：
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
如果使用require_once或者include_once，只要包含路徑正確，那么循環(huán)只執(zhí)行一次。
總結(jié)：
使用require，如果文件沒(méi)有包含成功，就會(huì)報(bào)出一個(gè)fatal error，整個(gè)程序就中止了。
使用include，如果文件沒(méi)有包含成功，就會(huì)報(bào)出一個(gè)普通的warning，之后的代碼仍會(huì)執(zhí)行。
如果你的Web程序使用了MVC這種對(duì)文件包含強(qiáng)依賴的設(shè)計(jì)方法，請(qǐng)使用require_once。
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