匹配准确的单词与任何字符regex-Matchexactwordwithanycharacterregex

3  

The problem is with \b word boundary before # non-word character. \b cannot match the position between 2 non-word (or between 2 word) characters, thus, you do not get a match.

问题是在# non-word字符前使用\b字边界。\b不能匹配两个非单词(或两个单词)字符之间的位置，因此不能匹配。

A solution is either to remove the first \b, or use \B (a non-word boundary matching between 2 word or 2 non-word characters) instead of it.

解决方案是删除第一个\b，或者使用\b(两个单词或两个非单词字符之间的非单词边界匹配)代替它。

\B#worldemojiday\b

Or

或

#worldemojiday\b

See demo (or this one)

见demo(或这个)

Note that \B also matches at the beginning of a string.

注意，\B也匹配字符串的开头。

Here is a way to build a regex dynamically, adding word boundaries only where necessary:

这里有一种动态构建regex的方法，只在必要时添加单词边界:

$srch = "žvolen";
$srch = preg_quote($srch);
if (preg_match('/\w$/u', $srch)) {
    $srch .= '\\b';   
}

if (preg_match('/^\w/u', $srch)) {
    $srch = '\\b' . $srch;
}
echo preg_match("/" . $srch . "/ui", "žvolen is used.");

1  

What about using lookarounds:

如何使用看看:

(?