string Scala - 大小写匹配部分字符串
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Scala - case match partial string
提问by jhdevuk
I have the following:
我有以下几点：
serv match {
case "chat" => Chat_Server ! Relay_Message(serv)
case _ => null
}
The problem is that sometimes I also pass an additional param on the end of the serv string, so:
问题是有时我还会在 serv 字符串的末尾传递一个额外的参数，所以：
var serv = "chat.message"
Is there a way I can match a part of the string so it still gets sent to Chat_Server?
有没有办法可以匹配字符串的一部分，以便它仍然被发送到 Chat_Server？
Thanks for any help, much appreciated :)
感谢您的帮助，非常感谢:)
回答by Kyle
Have the pattern matching bind to a variable and use a guardto ensure the variable begins with "chat"
将模式匹配绑定到一个变量并使用保护来确保变量以“chat”开头
// msg is bound with the variable serv
serv match {
case msg if msg.startsWith("chat") => Chat_Server ! Relay_Message(msg)
case _ => null
}
回答by om-nom-nom
Use regexes ;)
使用正则表达式 ;)
val Pattern = "(chat.*)".r
serv match {
case Pattern(chat) => "It's a chat"
case _ => "Something else"
}
And with regexes you can even easily split parameter and base string:
使用正则表达式，您甚至可以轻松拆分参数和基本字符串：
val Pattern = "(chat)(.*)".r
serv match {
case Pattern(chat,param) => "It's a %s with a %s".format(chat,param)
case _ => "Something else"
}
回答by jverce
In case you want to dismiss any groupings when using regexes, make sure you use a sequence wildcard like _*(as per Scala's documentation).
如果您想在使用正则表达式时取消任何分组，请确保使用序列通配符_*（根据Scala 的文档）。
From the example above:
从上面的例子：
val Pattern = "(chat.*)".r
serv match {
case Pattern(_*) => "It's a chat"
case _ => "Something else"
}
