简单的 preg_replace [英] Simple preg_replace

问题描述

我根本无法弄清楚 preg_replace，它对我来说只是中文，无论如何我只需要从字符串中删除&page-X"(如果它在那里).

I cant figure out preg_replace at all, it just looks chinese to me, anyway I just need to remove "&page-X" from a string if its there.

X 当然是一个数字，如果有人有一个链接到一个有用的 preg_replace 初学者教程，那也会很方便！

X being a number of course, if anyone has a link to a useful preg_replace tutorial for beginners that would also be handy!

推荐答案

实际上，preg_replace 和朋友支持的正则表达式的基本语法非常容易学习.将其视为描述具有特殊含义的某些字符的模式的字符串.

Actually the basic syntax for regular expressions, as supported by preg_replace and friends, is pretty easy to learn. Think of it as a string describing a pattern with certain characters having special meaning.

在您非常简单的情况下，可能的模式是:

In your very simple case, a possible pattern is:

&page-\d+

其中 \d 表示数字(数字字符 0-9)和 + 表示:在 + 之前重复表达式(此处:\d) 一次或多次.所有其他角色都代表他们自己.

With \d meaning a digit (numeric characters 0-9) and + meaning: Repeat the expression right before + (here: \d) one or more times. All other characters just represent themselves.

因此，上面的模式匹配以下任何字符串:

Therefore, the pattern above matches any of the following strings:

&page-0
&page-665
&page-1234567890

由于 preg 函数使用与 Perl 兼容的语法，并且正则表达式在 Perl 中用斜杠 (/) 表示，因此您必须将模式括在斜杠中:

Since the preg functions use a Perl-compatible syntax and regular expressions are denoted between slashes (/) in Perl, you have to surround the pattern in slashes:

$after = preg_replace('/&page-\d+/', '', $before);

实际上，您也可以使用其他字符:

Actually, you can use other characters as well:

$after = preg_replace('#&page-\d+#', '', $before);

有关受支持语法的完整参考，请参阅 PHP 手册.

For a full reference of supported syntax, see the PHP manual.

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