blocks|key|1305487|text|您可以定义如下模式：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1305488|scala>+val+Email+=+"""(\w%2B)@([\w\.]%2B)""".r|code-block|syntax|javascript|1305489|如果匹配，findFirstIn将返回Some[String]，否则将返回None。|offset|length|style|CODE|1305490|scala>+Email.findFirstIn("test@example.com")
res1:+Option[String]+=+Some(test@example.com)

scala>+Email.findFirstIn("test")
rest2:+Option[String]+=+None|1305491|你甚至可以提取：|1305492|scala>+val+Email(name,+domain)+=+"test@example.com"
name:+String+=+test
domain:+String+=+example.com|1305493|最后，您还可以使用常规的String.matches方法(甚至回收先前定义的Email+Regexp：|1305494|scala>+"david@example.com".matches(Email.toString)
res6:+Boolean+=+true|1305495|希望这能帮上忙。|1305496|entityMap^0|0|0|5|B|J|C|11|4|0|0|0|0|C|E|12|C|0|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|11|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|12|8|@$I|13|J|14|K|L]|$I|15|J|16|K|L]|$I|17|J|18|K|L]]|9|@]|A|$]]|$1|M|3|N|5|D|7|19|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|1A|8|@]|9|@]|A|$]]|$1|Q|3|R|5|D|7|1B|8|@]|9|@]|A|$E|F]]|$1|S|3|T|5|6|7|1C|8|@$I|1D|J|1E|K|L]|$I|1F|J|1G|K|L]]|9|@]|A|$]]|$1|U|3|V|5|D|7|1H|8|@]|9|@]|A|$E|F]]|$1|W|3|X|5|6|7|1I|8|@]|9|@]|A|$]]|$1|Y|3|-4|5|6|7|1J|8|@]|9|@]|A|$]]]|Z|$]]

You can define a pattern like this :

<pre><code>scala&gt; val Email = """(\w+)@([\w\.]+)""".r
</code></pre>

<code>findFirstIn</code> will return <code>Some[String]</code> if it matches or else <code>None</code>.

<pre><code>scala&gt; Email.findFirstIn("test@example.com")
res1: Option[String] = Some(test@example.com)

scala&gt; Email.findFirstIn("test")
rest2: Option[String] = None
</code></pre>

You could even extract :

<pre><code>scala&gt; val Email(name, domain) = "test@example.com"
name: String = test
domain: String = example.com
</code></pre>

Finally, you can also use conventional <code>String.matches</code> method (and even recycle the previously defined <code>Email Regexp</code> :

<pre><code>scala&gt; "david@example.com".matches(Email.toString)
res6: Boolean = true
</code></pre>

Hope this will help.

blocks|key|3619667|text|我为这个问题创建了一个小小的“拉皮条我的图书馆”模式。也许它能帮到你。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3619668|import+util.matching.Regex

object+RegexUtils+{
++class+RichRegex(self:+Regex)+{
++++def+=~(s:+String)+=+self.pattern.matcher(s).matches
++}
++implicit+def+regexToRichRegex(r:+Regex)+=+new+RichRegex(r)
}|code-block|syntax|javascript|3619669|使用实例|3619670|scala>+import+RegexUtils._
scala>+"""\w%2B""".r+=~+"foo"
res12:+Boolean+=+true|3619671|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

I created a little "Pimp my Library" pattern for that problem. Maybe it'll help you out.

<pre><code>import util.matching.Regex

object RegexUtils {
 class RichRegex(self: Regex) {
 def =~(s: String) = self.pattern.matcher(s).matches
 }
 implicit def regexToRichRegex(r: Regex) = new RichRegex(r)
}
</code></pre>

Example of use

<pre><code>scala&gt; import RegexUtils._
scala&gt; """\w+""".r =~ "foo"
res12: Boolean = true
</code></pre>

blocks|key|3636898|text|目前(2014年8月，Scala2.11)@David的回复告诉了规范。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3636899|但是，似乎r."..."字符串内插器正在帮助实现这一点。请参阅How+to+pattern+match+using+regular+expression+in+Scala?|offset|length|style|CODE|3636900|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/4636610/regular-expression-and-pattern-matching-in-scala#16256935^0|0|5|7|V|1J|0|0^^$0|@$1|2|3|4|5|6|7|P|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|Q|8|@$D|R|E|S|F|G]]|9|@$D|T|E|U|1|V]]|A|$]]|$1|H|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|I|$J|$5|K|L|M|A|$N|O]]]]

Currently (Aug 2014, Scala 2.11) @David's reply tells the norm.

However, it seems the <code>r."..."</code> string interpolator may be on its way to help with this. See <a href="https://stackoverflow.com/questions/4636610/regular-expression-and-pattern-matching-in-scala#16256935">How to pattern match using regular expression in Scala?</a>

blocks|key|3619690|text|我通常用|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3619691|val+regex+=+"...".r
if+(regex.findFirstIn(text).isDefined)+...|code-block|syntax|javascript|3619692|但我觉得这很尴尬。|3619693|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

I usually use

<pre><code>val regex = "...".r
if (regex.findFirstIn(text).isDefined) ...
</code></pre>

but I think that is pretty awkward.

I fairly frequently match strings against regular expressions. In Java:

java.util.regex.Pattern.compile("\w+").matcher("this_is").matches

Ouch. Scala has many alternatives.

<ol>
<li><code>"\\w+".r.pattern.matcher("this_is").matches</code></li>
<li><code>"this_is".matches("\\w+")</code></li>
<li><code>"\\w+".r unapplySeq "this_is" isDefined</code></li>
<li><code>val R = "\\w+".r; "this_is" match { case R() =&gt; true; case _ =&gt; false}</code></li>
</ol>

The first is just as heavy-weight as the Java code.

The problem with the second is that you can't supply a compiled pattern (<code>"this_is".matches("\\w+".r")</code>). (This seems to be an anti-pattern since almost every time there is a method that takes a regex to compile there is an overload that takes a regex).

The problem with the third is that it abuses <code>unapplySeq</code> and thus is cryptic.

The fourth is great when decomposing parts of a regular expression, but is too heavy-weight when you only want a boolean result.

Am I missing an easy way to check for matches against a regular expression? Is there a reason why <code>String#matches(regex: Regex): Boolean</code> is not defined? In fact, where is <code>String#matches(uncompiled: String): Boolean</code> defined?

Matching against a regular expression in Scala

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

文章

问答

视频

学习中心

腾讯云实验室

直播

竞赛

腾讯云代码分析专区

腾讯iOA零信任安全管理系统专区

腾讯云架构师技术同盟交流圈

腾讯云数据库专区

腾讯云顾问专区

腾讯云原生专区

腾讯混元专区

腾讯云TCE专区

腾讯云Lighthouse专区

腾讯云HAI专区

腾讯云Edgeone专区

腾讯云存储专区

腾讯云智能专区

腾讯轻联专区 

腾讯云开发专区

TAPD专区

腾讯轻量云游戏服专区

腾讯云最具价值专家

腾讯云架构师技术同盟

腾讯云创作之星

腾讯云开发者先锋

腾讯云代码助手

云原生构建

TAPD 敏捷项目管理

Cloud Studio

SDK中心

API中心

命令行工具

涵盖代码开发、场景应用、自动测试全流程，助你从零构建专属AI助手

一站式MCP教程库，解锁AI应用新玩法

我经常将字符串与正则表达式匹配。在Java中：java.util.regex.Pattern.compile("\w+").matcher("this_is").matches唉哟。Scala有很多选择。"\\w+".r.pattern.matcher("this_is").matches"this_is".match...

问与Scala中的正则表达式匹配
EN

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问与Scala中的正则表达式匹配EN