如何匹配重复模式？ [英] How to match repeated patterns?

问题描述

我想要匹配：

some.name.separated.by.dots

但我不知道怎么做。

我可以匹配这样的单个部分

I can match a single part like this

 \w+\.

我怎么说重复那个

推荐答案

请尝试以下方法：

\w+(\.\w+)+

<$ c后 + $ c>（...）告诉它与括号内的内容匹配一次或多次。

The + after ( ... ) tell it to match what is inside the parenthesis one or more times.

注意 \w 仅匹配ASCII字符，因此像café这样的单词不会与 \w +匹配，更不用说包含Unicode的单词/文字。

Note that \w only matches ASCII characters, so a word like café wouldn't be matches by \w+, let alone words/text containing Unicode.

之间的区别 [...] 和（...）是 [...] 始终匹配单个字符。它被称为字符集或字符类。所以， [abc] 不匹配字符串abc，但匹配一个字符 a ， b 或 c 。

The difference between [...] and (...) is that [...] always matches a single character. It is called a "character set" or "character class". So, [abc] does not match the string "abc", but matches one of the characters a, b or c.

\w + [\.\w +] * 的事实也与你的字符串匹配，因为 [\.\w +] 匹配。或来自 \w ，然后由 * 重复零次或多次。但是， \w + [\.\w +] * 也会匹配 aaaaa 或<$等字符串c $ c> aaa ........... 。

The fact that \w+[\.\w+]* also matches your string is because [\.\w+] matches a . or a character from \w, which is then repeated zero or more time by the * after it. But, \w+[\.\w+]* will therefor also match strings like aaaaa or aaa............

（... ），正如我已经提到的，只是用于对字符进行分组（并且可能重复这些组）。

The (...) is, as I already mentioned, simply used to group characters (and possible repeat those groups).

有关字符集的更多信息：< a href =http://www.regular-expressions.info/charclass.html =noreferrer> http://www.regular-expressions.info/charclass.html

More info on character sets: http://www.regular-expressions.info/charclass.html

有关群组的更多信息： http：//www.regular- expressions.info/brackets.html

More info on groups: http://www.regular-expressions.info/brackets.html

这是Java中的一个例子（见你主要发表Java答案）：

Here's an example in Java (seeing you post mostly Java answers):

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Main {
    public static void main(String[] args) {
        String text = "some.text.here only but not Some other " + 
                "there some.name.separated.by.dots and.we are done!";
        Pattern p = Pattern.compile("\\w+(\\.\\w+)+");
        Matcher m = p.matcher(text);
        while(m.find()) {
            System.out.println(m.group());
        }
    }
}

将产生：

some.text.here
some.name.separated.by.dots
and.we

请注意 m.group（0）和 m.group（）是等价的：意思是整场比赛。

Note that m.group(0) and m.group() are equivalent: meaning "the entire match".

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