php 正则表达式的任何字符表示法
在我的正则表达式中，我想说在示例文本中，允许使用任何字符，包括大写和小写的 az、数字和特殊字符。
例如，我的正则表达式可能会检查文档是否为 html。因此：
"/\n<html>[]+</html>\n/"
我尝试过 []+ 但它似乎不喜欢这样？
In my regex, I want to say that within the sample text, any characters are allowed, including a-z in upper and lower case, numbers and special characters.
For example, my regular expression may be checking that a document is html. therefore:
"/\n<html>[]+</html>\n/"
i have tried []+ but it does not seem to like this?
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使用
[XXX]+表示[和]之间的任何字符一次或多次。在这里，您没有在
[和]之间放置任何字符 - 因此出现了问题。If you want to say "any possible character", you can use a `.`
Note : by default, it will not match newlines ; you'll have to play with [**Pattern Modifiers**][1] if you want it to.
如果您想说出任何字母，您可以使用 :
[az][AZ][a- zA-Z]并且，对于数字：
[0-9]：任何数字[a-zA-Z0-9]：任何小写或大写字母和任何数字。At that point, you will probably want to take a look at :
\w元字符，表示“任何单词字符”，After that, when you'll begin using a regex such as
应匹配：
您会发现它在您期望时也不会“停止”——那是因为默认情况下匹配是贪婪的——您必须使用
?在+之后，或使用U修饰符；请参阅重复部分，了解更多信息。Well, actually, the best thing to do would be to *invest* some time, carefully reading everything in the [**PCRE Patterns**][4] section of the manual, if you want to start working with regexes ;-)
Oh, and, BTW : **using regex to *parse* HTML is a bad idea...**
通常使用 DOM 解析器会更好，例如：
DOMDocument::loadHTMLUsing
[XXX]+means any character that's between[and], one or more than one time.Here, you didn't put any character between
[and]-- hence the problem.If you want to say "any possible character", you can use a `.`
Note : by default, it will not match newlines ; you'll have to play with [**Pattern Modifiers**][1] if you want it to.
If you want to say any letter, you can use :
[a-z][A-Z][a-zA-Z]And, for numbers :
[0-9]: any digit[a-zA-Z0-9]: any lower-case or upper-case letter, and any number.At that point, you will probably want to take a look at :
\wmeta-character, which means "any word character"After that, when you'll begin using a regex such as
which should match :
You'll see that it doesn't "stop" when you expect it too -- that's because matching is greedy, by default -- you'll have to use a
?after the+, or use theUmodifier ; see the Repetition section, for more informations.Well, actually, the best thing to do would be to *invest* some time, carefully reading everything in the [**PCRE Patterns**][4] section of the manual, if you want to start working with regexes ;-)
Oh, and, BTW : **using regex to *parse* HTML is a bad idea...**
It's generally much better to use a DOM Parser, such as :
DOMDocument::loadHTML点
.是“任何字符”的元字符the dot
.is the meta character for "any character"