{"id":134044,"date":"2020-07-21T04:20:41","date_gmt":"2020-07-20T20:20:41","guid":{"rendered":"http:\/\/4563.org\/?p=134044"},"modified":"2020-07-21T04:20:41","modified_gmt":"2020-07-20T20:20:41","slug":"scala%e8%af%ad%e8%a8%80%e5%ad%a6%e4%b9%a0%ef%bc%88%e4%b9%9d%ef%bc%89%e3%80%81%e6%8f%90%e5%8f%96%e5%99%a8extractor","status":"publish","type":"post","link":"http:\/\/4563.org\/?p=134044","title":{"rendered":"scala\u8bed\u8a00\u5b66\u4e60\uff08\u4e5d\uff09\u3001\u63d0\u53d6\u5668(Extractor)"},"content":{"rendered":"

<\/a>\u63d0\u53d6\u5668(Extractor)<\/h2>\n

\u63d0\u53d6\u5668\u662f\u4ece\u4f20\u9012\u7ed9\u5b83\u7684\u5bf9\u8c61\u4e2d\u63d0\u53d6\u51fa\u6784\u9020\u8be5\u5bf9\u8c61\u7684\u53c2\u6570\u3002(\u56de\u60f3\u6837\u4f8b\u7c7b\u8fdb\u884c\u6a21\u5f0f\u5339\u914d\u63d0\u53d6\u53c2\u6570)<\/p>\n

scala \u63d0\u53d6\u5668\u662f\u4e00\u4e2a\u5e26\u6709unapply\u65b9\u6cd5\u7684\u5bf9\u8c61\uff0cunapply\u65b9\u6cd5\u7b97\u662fapply\u65b9\u6cd5\u7684\u53cd\u5411\u64cd\u4f5c\uff0cunapply\u63a5\u53d7\u4e00\u4e2a\u5bf9\u8c61\uff0c\u7136\u540e\u4ece\u5bf9\u8c61\u4e2d\u63d0\u53d6\u503c\uff0c\u63d0\u53d6\u7684\u503c\u901a\u5e38\u662f\u7528\u6765\u6784\u9020\u8be5\u5bf9\u8c61\u7684\u503c\u3002<\/p>\n

\"scala\u8bed\u8a00\u5b66\u4e60\uff08\u4e5d\uff09\u3001\u63d0\u53d6\u5668(Extractor)\"<\/p>\n

\"scala\u8bed\u8a00\u5b66\u4e60\uff08\u4e5d\uff09\u3001\u63d0\u53d6\u5668(Extractor)\"<\/p>\n

\n\n\n
\n
1<\/span>
2<\/span>
3<\/span>
4<\/span>
5<\/span>
6<\/span>
7<\/span>
8<\/span>
9<\/span>
10<\/span>
11<\/span>
12<\/span>
13<\/span>
14<\/span>
15<\/span>
16<\/span>
17<\/span>
18<\/span>
19<\/span>
20<\/span>
21<\/span>
22<\/span>
23<\/span>
24<\/span>
25<\/span>
26<\/span>
27<\/span>
28<\/span>
29<\/span>
30<\/span>
<\/pre>\n<\/td>\n
\n
class<\/span> Student<\/span> <\/span>{<\/span>
  var<\/span> name:String<\/span> = _   \/\/ \u59d3\u540d<\/span><\/span>
  var<\/span> age:Int<\/span> = _       \/\/ \u5e74\u9f84<\/span><\/span>
  <\/span>
  \/\/ \u5b9e\u73b0\u4e00\u4e2a\u8f85\u52a9\u6784\u9020\u5668<\/span><\/span>
  def<\/span> this<\/span><\/span>(name:String<\/span>, age:Int<\/span>) = {<\/span>
    this<\/span>()<\/span>
    <\/span>
    this<\/span>.name = name<\/span>
    this<\/span>.age = age<\/span>
  }<\/span>
}<\/span>
<\/span>
object<\/span> Student<\/span> <\/span>{<\/span>
  def<\/span> apply<\/span><\/span>(name:String<\/span>, age:Int<\/span>): Student<\/span> = new<\/span> Student<\/span>(name, age)<\/span>
<\/span>
  \/\/ \u5b9e\u73b0\u4e00\u4e2a\u89e3\u6784\u5668<\/span><\/span>
  def<\/span> unapply<\/span><\/span>(arg: Student<\/span>): Option<\/span>[(String<\/span>, Int<\/span>)] = Some<\/span>(arg.name, arg.age))<\/span>
}<\/span>
<\/span>
object<\/span> extractor_DEMO<\/span> <\/span>{<\/span>
  def<\/span> main<\/span><\/span>(args: Array<\/span>[String<\/span>]): Unit<\/span> = {<\/span>
    val<\/span> zhangsan = Student<\/span>(\"\u5f20\u4e09\"<\/span>, 20<\/span>)<\/span>
<\/span>
    zhangsan match<\/span> {<\/span>
      case<\/span> Student<\/span>(name, age) => println(s\"\u59d3\u540d\uff1a$name<\/span> \u5e74\u9f84\uff1a$age<\/span>\"<\/span>)<\/span>
      case<\/span> _ => println(\"\u672a\u5339\u914d\"<\/span>)<\/span>
    }<\/span>
  }<\/span>
}<\/span>
<\/pre>\n<\/td>\n<\/tr>\n<\/table>\n<\/figure>\n","protected":false},"excerpt":{"rendered":"
\u63d0\u53d6\u5668(Extractor) \u63d0\u53d6…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[],"tags":[],"_links":{"self":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/134044"}],"collection":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=134044"}],"version-history":[{"count":0,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/134044\/revisions"}],"wp:attachment":[{"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=134044"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=134044"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=134044"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}