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PHP语言中include和require的区别

本文主要介绍了PHP语言中include和require的区别。今天我们就通过一个具体的实例来简单分析下

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 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 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。

以上就是本文PHP语言中include和require的区别的全部内容,欢迎大家的学习。

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