Higher-Order Functions<\/h2> \n \n def<\/code> \u5b9a\u4e49\u7684\u662f\u65b9\u6cd5\uff0c\u800c\u4e0d\u662f\u51fd\u6570<\/li> \n - \u51fd\u6570\u53ef\u4f5c\u4e3a\u53d8\u91cf\u5b58\u5728\uff0c\u53ef\u76f4\u63a5\u8c03\u7528\uff0c\u4e5f\u53ef\u4f5c\u4e3a\u503c\u4f20\u9012\u7ed9\u5176\u4ed6\u51fd\u6570<\/li> \n
_<\/code> \u540e\u7f00\u5c06\u666e\u901a\u65b9\u6cd5\u53d8\u4e3a\u51fd\u6570: ceil _<\/code> \n \n - \u6839\u636e\u4e0a\u4e0b\u6587\u7f16\u8bd1\u5668\u53ef\u4ee5\u81ea\u52a8\u5c06\u65b9\u6cd5\u8f6c\u6362\u4e3a\u51fd\u6570\uff0c\u4e5f\u53ef\u7701\u7565
_<\/code> \u540e\u7f00<\/li> \n <\/ul><\/li> \n - \u9ad8\u9636\u51fd\u6570\uff0c\u63a5\u6536\u51fd\u6570\u7684\u51fd\u6570<\/li> \n
- \u53c2\u6570\u7c7b\u578b\u63a8\u5bfc \n
\n - \u533f\u540d\u51fd\u6570\u4f20\u9012\u7ed9\u5176\u4ed6\u51fd\u6570\u6216\u65b9\u6cd5\u65f6\uff0c\u5982\u679c\u4e00\u76f4\u5230\u53c2\u6570\u7c7b\u578b\uff0c\u5219\u53ef\u7701\u7565\u533f\u540d\u51fd\u6570\u7684\u53c2\u6570\u7c7b\u578b\uff0c\u53ef\u81ea\u52a8\u63a8\u5bfc\u7c7b\u578b<\/li> \n
- \u53c2\u6570\u53ea\u6709\u4e00\u4e2a\u65f6\u53ef\u7701\u7565\u62ec\u53f7 \n
\n - \u5f53\u53c2\u6570\u5728\u53f3\u4fa7\u53ea\u51fa\u73b0\u4e00\u6b21\u65f6\uff0c\u53ef\u4f7f\u7528
_<\/code> \u7b80\u5199<\/li> \n <\/ul><\/li> \n <\/ul><\/li> \n - \u95ed\u5305 Closures\uff0c\u7279\u5b9a\u4f5c\u7528\u57df<\/li> \n
- SAM, single abstract method interface \n
\n - \u5bf9\u5e94 Java \u4e2d\u7684\u51fd\u6570\u5f0f\u63a5\u53e3 (1.8)<\/li> \n
- \u53ef\u5c06 Scala \u51fd\u6570\u4f20\u9012\u7ed9 Java\uff0c\u53ea\u5728\u51fd\u6570\u5b57\u9762\u91cf\u4e2d\u8d77\u4f5c\u7528<\/strong><\/li> \n <\/ul><\/li> \n
- \u67ef\u91cc\u5316 Currying \n
\n - \u5c06\u63a5\u6536\u4e24\u4e2a\u53c2\u6570\u7684\u51fd\u6570\u53d8\u4e3a\u63a5\u6536\u7b2c\u4e00\u4e2a\u53c2\u6570\u7684\u51fd\u6570\uff0c\u8be5\u51fd\u6570\u8fd4\u56de\u4e00\u4e2a\u6d88\u8d39\u7b2c\u4e8c\u4e2a\u53c2\u6570\u7684\u51fd\u6570<\/li> \n <\/ul><\/li> \n
- \u63a7\u5236\u62bd\u8c61 Control Abstractions \n
\n - Scala \u53ea\u5305\u542b\u5c11\u91cf\u7684\u6d41\u7a0b\u63a7\u5236\u8bed\u53e5\uff0c\u7528\u6237\u53ef\u81ea\u5b9a\u4e49\u63a7\u5236\u8bed\u53e5<\/li> \n <\/ul><\/li> \n <\/ul> \n
Pattern Matching and Case Classes<\/h2> \n \n - \u53ef\u5bf9\u4efb\u4f55\u7c7b\u578b\u8fdb\u884c\u6a21\u5f0f\u5339\u914d\uff0c\u5339\u914d\u987a\u5e8f\u4ece\u4e0a\u81f3\u4e0b<\/li> \n
- \u6a21\u5f0f\u5339\u914d\u4ee3\u66ff
switch<\/code>\uff0c\u9ed8\u8ba4\u5206\u652f\u4e3a case _<\/code>\uff1b\u53ef\u907f\u514d switch<\/code> \u8bed\u53e5\u4e2d\u56e0\u7f3a\u5c11 break<\/code> \u5e26\u6765\u7684 fall-through<\/code> \u95ee\u9898<\/li> \n - \u6a21\u5f0f\u5339\u914d\u4e5f\u662f\u8868\u8fbe\u5f0f\uff0c\u53ef\u5c06\u5176\u8fd4\u56de\u503c\u76f4\u63a5\u8d4b\u503c\u7ed9\u53d8\u91cf<\/li> \n
- \u6a21\u5f0f\u5b88\u536b \/ guards\uff0c\u4e3a\u5339\u914d\u8bbe\u7f6e\u6761\u4ef6\uff0c\u4efb\u4f55
Boolean<\/code> \u6761\u4ef6\u90fd\u53ef\u4f5c\u4e3a\u6a21\u5f0f\u5b88\u536b\uff1bcase ... if ... => ...<\/code><\/li> \n case<\/code> \u5173\u952e\u5b57\u540e\u63a5\u53d8\u91cf\u540d\u6216\u5bf9\u5e94\u6570\u636e\u7ed3\u6784\u4e2d\u4f7f\u7528\u53d8\u91cf\u540d\uff0c\u90a3\u4e48\u5339\u914d\u9879\u5c31\u8d4b\u503c\u7ed9\u8be5\u53d8\u91cf\uff0c\u53d8\u91cf\u540d\u5fc5\u987b\u4ee5\u5c0f\u5199\u5b57\u6bcd\u5f00\u5934<\/strong><\/li> \n - \u4f7f\u7528
|<\/code> \u5206\u9694\u540c\u4e00\u5339\u914d\u7684\u591a\u4e2a\u53ef\u9009\u9879\uff0c\u6b64\u65f6\u4e0d\u53ef\u4f7f\u7528\u53d8\u91cf\u7ed1\u5b9a\u5143\u7d20<\/strong><\/li> \n - \u7c7b\u578b\u5339\u914d\uff0c\u4ee3\u66ff
isInstanceOf<\/code> \u548c asInstanceOf<\/code>\uff0c\u76f4\u63a5\u8fdb\u884c\u7c7b\u578b\u8f6c\u6362 \n \n - \u5fc5\u987b\u4e3a\u7c7b\u578b\u6307\u5b9a\u53d8\u91cf\u540d\uff0c\u5426\u5219\u5339\u914d\u7684\u662f\u5b9e\u9645\u7684\u7c7b\u578b\u5bf9\u8c61<\/li> \n
- \u5339\u914d\u5728\u8fd0\u884c\u65f6\u53d1\u751f\uff0c\u800c JVM \u6cdb\u578b\u4f1a\u88ab\u64e6\u9664 \n
\n - \u4e0d\u53ef\u4ee5\u5339\u914d\u5177\u4f53\u7684
Map<\/code> \u7c7b\u578b\uff08\u53ef\u4f7f\u7528 case Map[_, _]<\/code>\uff0c\u4e0d\u53ef\u4f7f\u7528 case Map[Int, Int]<\/code>\uff09<\/li> \n Array<\/code> \u7684\u7c7b\u578b\u4e0d\u4f1a\u88ab\u64e6\u9664<\/li> \n <\/ul><\/li> \n <\/ul><\/li> \n - \u89e3\u6784 destructuring \n
\n \u5339\u914d\u6570\u7ec4<\/p>
case Array(x, y) => s"$x $y" \/\/ \u5339\u914d\u957f\u5ea6\u4e3a2\u7684\u6570\u7ec4\uff0c\u5e76\u5c06\u5206\u522b\u7ed1\u5b9a\u5230 x, y\ncase Array(0, rest @ _*) => rest.min \/\/ \u53ef\u53d8\u53c2\u6570<\/code><\/pre><\/li> \n \u5339\u914d List<\/code><\/p> case x :: y :: Nil => ... \/\/ \u7ed1\u5b9a\u53c2\u6570\ncase head :: tail => ... \/\/ \u89e3\u6784 head , tail<\/code><\/pre><\/li> \n \u5339\u914d\u5143\u7ec4<\/p>
case (0, _) => ... \/\/ \u5339\u914d\u7b2c\u4e00\u4e2a\u5143\u7d20\u4e3a0\ncase (x, y) => ... \/\/ \u7ed1\u5b9a\u53c2\u6570<\/code><\/pre><\/li> \n <\/ul><\/li> \n - \u5b9a\u4e49\u53d8\u91cf\uff0c\u6ce8\u610f\u4e00\u5b9a\u8981\u5c0f\u5199\u5f00\u5934<\/strong>\uff1b\u5176\u5b9e\u7b49\u4ef7\u4e8e
match<\/code> \u6a21\u5f0f\u5339\u914d\u52a0\u4e0a\u8d4b\u503c\u64cd\u4f5c \n \n val (x, y) = (1, 2)<\/code><\/li> \n val Array(f, s, rest @ _*) = arr<\/code><\/li> \n <\/ul><\/li> \n \u7528\u4e8e for<\/code> \u5faa\u73af\u904d\u5386\u96c6\u5408\uff0c\u5339\u914d\u7b26\u5408\u6761\u4ef6\u7684\u5143\u7d20<\/p> for ((k, v) <- System.getProperties()) println(s"$k $v")\n\/\/ \u5339\u914d value \u4e3a "" \u7684\u9879\uff0c\u5176\u4ed6\u7684\u5219\u88ab\u5ffd\u7565\nfor ((k, "") <- System.getProperties()) println(k)\n\/\/ if guard \u8fc7\u6ee4\nfor ((k, v) <- System.getProperties() if v == "") println(k)<\/code><\/pre><\/li> \n - Case Class \n
\n - \u7528\u4e8e\u6a21\u5f0f\u5339\u914d\u7684\u7279\u6b8a\u7c7b<\/li> \n
- \u6784\u9020\u53c2\u6570\u9ed8\u8ba4\u4e3a
val<\/code>\uff0c\u9ed8\u8ba4\u63d0\u4f9b apply<\/code>\u3001unapply<\/code>\u3001toString<\/code>\u3001equals<\/code>\u3001hashCode<\/code>\u3001copy<\/code> \n \n copy<\/code> \u7528\u4e8e\u590d\u5236\u5bf9\u8c61\u65f6\uff0c\u53ef\u4f7f\u7528\u547d\u540d\u53c2\u6570\u6765\u4fee\u6539\u5c5e\u6027<\/li> \n <\/ul><\/li> \n case class X<\/code> \u4f7f\u7528\u65f6 case X() => ...<\/code>\uff0c\u9700\u8981\u62ec\u53f7<\/li> \n case object S<\/code> \u5355\u4f8b\uff0c\u4f7f\u7528\u65f6 case S => ...<\/code>\uff0c \u4e0d\u8981\u62ec\u53f7<\/li> \n ::<\/code> \u4e5f\u662f case class\uff0c\u914d\u5408\u4e2d\u7f00\u8868\u8fbe\u5f0f\uff0c\u5c31\u662f\u5e38\u89c1\u7684\u5339\u914d\u65b9\u5f0f\uff0ccase head :: tail<\/code>\uff0c\u5b9e\u9645\u8c03\u7528 ::(head, tail)<\/code><\/li> \n - \u53ef\u7528\u4e8e\u5d4c\u5957\u7684\u7ed3\u6784\uff1b\u7ed1\u5b9a\u53d8\u91cf\u3001\u53ef\u53d8\u53c2\u6570\u5339\u914d\u7c7b\u4f3c<\/li> \n
- \u9002\u7528\u4e8e\u56fa\u5b9a\u7ed3\u6784\u7684\u7c7b\uff0c\u5982
List<\/code> \u7b49<\/li> \n <\/ul><\/li> \n sealed<\/code> \u5bc6\u5c01\u7684 \n \n - \u88ab\u4fee\u9970\u7684\u7c7b\uff0c\u5219\u5176\u5b50\u7c7b\u5fc5\u987b\u548c\u8be5\u7c7b\u5728\u540c\u4e00\u4e2a\u6587\u4ef6\u4e2d\u5b9a\u4e49<\/li> \n
- \u5728\u7f16\u8bd1\u65f6\u5373\u786e\u5b9a\u4e86\u6240\u6709\u5339\u914d\u9879\u7684\u53ef\u80fd\u6027<\/li> \n <\/ul><\/li> \n
Option<\/code> \u4e5f\u662f\u4f7f\u7528 case class \u6765\u8868\u793a\u662f\u5426\u6709\u503c\u5b58\u5728\u7684 \n \n - \u5b50\u7c7b
Some<\/code> \u5c01\u88c5\u503c\uff0c\u5b50\u7c7b None<\/code> \u8868\u793a\u65e0\u503c<\/li> \n - \u76f8\u6bd4\u4f7f\u7528
""<\/code> \u6216 null<\/code> \u66f4\u52a0\u5b89\u5168<\/li> \n Map<\/code> \u8fdb\u884c get<\/code> \u64cd\u4f5c\u8fd4\u56de\u7684\u4e5f\u662f Option<\/code>\uff0c\u4e5f\u53ef\u4f7f\u7528\u6a21\u5f0f\u5339\u914d\u6765\u5904\u7406<\/li> \n getOrElse<\/code> \u5c1d\u8bd5\u83b7\u53d6\u503c\uff0c\u672a\u83b7\u53d6\u5230\u5219\u4f7f\u7528\u7ed9\u5b9a\u7684\u503c<\/li> \n <\/ul><\/li> \n - Partial Function \u504f\u51fd\u6570 \n
\n - \u6ca1\u6709\u5bf9\u6240\u6709\u8f93\u5165\u8fdb\u884c\u5b9a\u4e49\u7684\u51fd\u6570<\/li> \n
apply<\/code> \u4ece\u6a21\u5f0f\u5339\u914d\u4e2d\u8ba1\u7b97\u51fd\u6570\u503c\uff0cisDefinedAt<\/code> \u5224\u65ad\u8f93\u5165\u662f\u5426\u5339\u914d\u5b9a\u4e49\u7684\u6a21\u5f0f<\/li> \n case<\/code> \u8bed\u53e5\u5757\u662f\u504f\u51fd\u6570<\/li> \n PartialFunction[A, B]<\/code> \u7684\u5b9e\u4f8b\uff0c A<\/code> \u4e3a\u8f93\u5165\u7c7b\u578b\uff0cB<\/code> \u4e3a\u8f93\u51fa\u7c7b\u578b \n \n - \u53ef\u4f7f\u7528\u504f\u51fd\u6570\u7684
lift<\/code> \u65b9\u6cd5\uff0c\u5c06\u504f\u51fd\u6570\u53d8\u4e3a\u5e38\u89c4\u51fd\u6570\uff0c\u8fd4\u56de\u503c\u4e3a Option[B]<\/code><\/li> \n - \u4e5f\u53ef\u4ee5\u901a\u8fc7
Function.unlift<\/code> \u5c06\u8fd4\u56de Option[B]<\/code> \u7684\u51fd\u6570\u53d8\u4e3a\u504f\u51fd\u6570<\/li> \n <\/ul><\/li> \n Seq[A]<\/code> \u4e5f\u662f\u504f\u51fd\u6570 PartialFunction[Int, A]<\/code><\/li> \n Map[K, V]<\/code> \u4e5f\u662f\u504f\u51fd\u6570 PartialFunction[K, V]<\/code><\/li> \n catch<\/code> \u8bed\u53e5\u4e5f\u662f\u504f\u51fd\u6570\uff0c\u53ef\u5728 catch<\/code> \u5757\u4e2d\u4f7f\u7528\u6a21\u5f0f\u5339\u914d\u5904\u7406\u5f02\u5e38<\/li> \n <\/ul><\/li> \n <\/ul> \n \u6ce8\u89e3<\/h2> \n \n - Scala \u4e2d\u6ce8\u89e3\u53ef\u5f71\u54cd\u4ee3\u7801\u7f16\u8bd1\uff0c\u5982
@BeanProperty<\/code> \u4f1a\u81ea\u52a8\u751f\u6210 getter\/setter<\/code><\/li> \n - \u53ef\u7528\u4e8e \u7c7b\u3001\u65b9\u6cd5\u3001\u5b57\u6bb5\u3001\u53d8\u91cf\u3001\u53c2\u6570\u7b49 \n
\n - \u591a\u4e2a\u6ce8\u89e3\u65e0\u987a\u5e8f<\/li> \n
- \u4e3b\u6784\u9020\u5668\u7684\u6ce8\u89e3\uff0c\u9700\u8981\u52a0\u62ec\u53f7
class Credential @Inject() (var username: String, var password: String)<\/code><\/li> \n - \u8868\u8fbe\u5f0f\u7684\u6ce8\u89e3\uff0c\u4f7f\u7528\u5206\u53f7\u52a0\u6ce8\u89e3\u7684\u65b9\u5f0f
(map.get(key): @unchecked) ...<\/code><\/li> \n - \u7c7b\u578b\u53c2\u6570\u7684\u6ce8\u89e3\uff0c
class Test[@specialized T]<\/code><\/li> \n - \u5b9e\u9645\u7c7b\u578b\u7684\u6ce8\u89e3\uff0c\u653e\u5728\u7c7b\u578b\u4e4b\u540e\uff0c
def name: String @Localized<\/code><\/li> \n <\/ul><\/li> \n - \u6ce8\u89e3\u5b9e\u73b0 \n
\n - \u6ce8\u89e3\u5fc5\u987b\u7ee7\u627f
Annotation<\/code><\/li> \n - \u7c7b\u578b\u6ce8\u89e3\u5fc5\u987b\u7ee7\u627f
TypeAnnotation<\/code><\/li> \n - \u5143\u6ce8\u89e3
@param<\/code>, @field<\/code>, @getter<\/code>, @setter<\/code>, @beanGetter<\/code>, @beanSetter<\/code><\/li> \n <\/ul><\/li> \n - \u5bf9\u5e94 Java \u4fee\u9970\u7b26\u3001\u6807\u8bb0\u63a5\u53e3 \n
\n @volatile<\/code> \u5bf9\u5e94 volatile<\/code> \u5173\u952e\u5b57<\/li> \n @transient<\/code> \u5bf9\u5e94 transient<\/code> \u5173\u952e\u5b57<\/li> \n @strictfp<\/code> \u5bf9\u5e94 strictfp<\/code> \u5173\u952e\u5b57<\/li> \n @native<\/code> \u5bf9\u5e94 native<\/code> \u5173\u952e\u5b57<\/li> \n @cloneable<\/code> \u5bf9\u5e94 Cloneable<\/code><\/li> \n @remote<\/code> \u5bf9\u5e94 java<\/a>.rmi.Remote<\/code><\/li> \n @SerialVersionUID<\/code> \u4ee3\u66ff\u5e8f\u5217\u5316\u5b57\u6bb5<\/li> \n <\/ul><\/li> \n - \u4f7f\u7528
@throws(classOf[Exception])<\/code> \u6765\u5904\u7406 Java \u4e2d\u7684\u53d7\u68c0\u5f02\u5e38<\/li> \n @varargs<\/code> \u5904\u7406\u53ef\u53d8\u53c2\u6570 \n \n @varargs def name(args: String*)<\/code> \u751f\u6210 void name(String... args)<\/code><\/li> \n - \u6ca1\u6709
@varargs<\/code> \u5219\u53ef\u53d8\u53c2\u6570\u4f1a\u88ab\u8f6c\u6362\u6210 Seq[T]<\/code><\/li> \n <\/ul><\/li> \n - \u4f18\u5316 \n
\n @tailrec<\/code> \u4f1a\u5c1d\u8bd5\u4f18\u5316\u5c3e\u9012\u5f52\u8c03\u7528\uff0c\u5c06\u5176\u53d8\u4e3a\u5faa\u73af<\/li> \n @switch<\/code> \u7f16\u8bd1\u5668\u4f1a\u68c0\u67e5 match<\/code> \u8868\u8fbe\u5f0f\u662f","orderid":"0","title":"Scala Class etc. 2(\u4e00)","smalltitle":"","mid":"0","fname":"Scala","special_id":"0","bak_id":"0","info":"0","hits":"294","pages":"2","comments":"0","posttime":"2019-10-09 20:01:14","list":"1570622474","username":"admin","author":"","copyfrom":"","copyfromurl":"","titlecolor":"","fonttype":"0","titleicon":"0","picurl":"https:\/\/www.cppentry.com\/upload_files\/","ispic":"0","yz":"1","yzer":"","yztime":"0","levels":"0","levelstime":"0","keywords":"Scala<\/A> Class<\/A> etc.<\/A>","jumpurl":"","iframeurl":"","style":"","template":"a:3:{s:4:\"head\";s:0:\"\";s:4:\"foot\";s:0:\"\";s:8:\"bencandy\";s:0:\"\";}","target":"0","ip":"14.17.22.32","lastfid":"0","money":"0","buyuser":"","passwd":"","allowdown":"","allowview":"","editer":"","edittime":"0","begintime":"0","endtime":"0","description":"Scala Class etc. 2","lastview":"1713380410","digg_num":"0","digg_time":"0","forbidcomment":"0","ifvote":"0","heart":"","htmlname":"","city_id":"0"},"page":"1"}
def<\/code> \u5b9a\u4e49\u7684\u662f\u65b9\u6cd5\uff0c\u800c\u4e0d\u662f\u51fd\u6570<\/li> \n - \u51fd\u6570\u53ef\u4f5c\u4e3a\u53d8\u91cf\u5b58\u5728\uff0c\u53ef\u76f4\u63a5\u8c03\u7528\uff0c\u4e5f\u53ef\u4f5c\u4e3a\u503c\u4f20\u9012\u7ed9\u5176\u4ed6\u51fd\u6570<\/li> \n
_<\/code> \u540e\u7f00\u5c06\u666e\u901a\u65b9\u6cd5\u53d8\u4e3a\u51fd\u6570: ceil _<\/code> \n \n - \u6839\u636e\u4e0a\u4e0b\u6587\u7f16\u8bd1\u5668\u53ef\u4ee5\u81ea\u52a8\u5c06\u65b9\u6cd5\u8f6c\u6362\u4e3a\u51fd\u6570\uff0c\u4e5f\u53ef\u7701\u7565
_<\/code> \u540e\u7f00<\/li> \n <\/ul><\/li> \n - \u9ad8\u9636\u51fd\u6570\uff0c\u63a5\u6536\u51fd\u6570\u7684\u51fd\u6570<\/li> \n
- \u53c2\u6570\u7c7b\u578b\u63a8\u5bfc \n
\n - \u533f\u540d\u51fd\u6570\u4f20\u9012\u7ed9\u5176\u4ed6\u51fd\u6570\u6216\u65b9\u6cd5\u65f6\uff0c\u5982\u679c\u4e00\u76f4\u5230\u53c2\u6570\u7c7b\u578b\uff0c\u5219\u53ef\u7701\u7565\u533f\u540d\u51fd\u6570\u7684\u53c2\u6570\u7c7b\u578b\uff0c\u53ef\u81ea\u52a8\u63a8\u5bfc\u7c7b\u578b<\/li> \n
- \u53c2\u6570\u53ea\u6709\u4e00\u4e2a\u65f6\u53ef\u7701\u7565\u62ec\u53f7 \n
\n - \u5f53\u53c2\u6570\u5728\u53f3\u4fa7\u53ea\u51fa\u73b0\u4e00\u6b21\u65f6\uff0c\u53ef\u4f7f\u7528
_<\/code> \u7b80\u5199<\/li> \n <\/ul><\/li> \n <\/ul><\/li> \n - \u95ed\u5305 Closures\uff0c\u7279\u5b9a\u4f5c\u7528\u57df<\/li> \n
- SAM, single abstract method interface \n
\n - \u5bf9\u5e94 Java \u4e2d\u7684\u51fd\u6570\u5f0f\u63a5\u53e3 (1.8)<\/li> \n
- \u53ef\u5c06 Scala \u51fd\u6570\u4f20\u9012\u7ed9 Java\uff0c\u53ea\u5728\u51fd\u6570\u5b57\u9762\u91cf\u4e2d\u8d77\u4f5c\u7528<\/strong><\/li> \n <\/ul><\/li> \n
- \u67ef\u91cc\u5316 Currying \n
\n - \u5c06\u63a5\u6536\u4e24\u4e2a\u53c2\u6570\u7684\u51fd\u6570\u53d8\u4e3a\u63a5\u6536\u7b2c\u4e00\u4e2a\u53c2\u6570\u7684\u51fd\u6570\uff0c\u8be5\u51fd\u6570\u8fd4\u56de\u4e00\u4e2a\u6d88\u8d39\u7b2c\u4e8c\u4e2a\u53c2\u6570\u7684\u51fd\u6570<\/li> \n <\/ul><\/li> \n
- \u63a7\u5236\u62bd\u8c61 Control Abstractions \n
\n - Scala \u53ea\u5305\u542b\u5c11\u91cf\u7684\u6d41\u7a0b\u63a7\u5236\u8bed\u53e5\uff0c\u7528\u6237\u53ef\u81ea\u5b9a\u4e49\u63a7\u5236\u8bed\u53e5<\/li> \n <\/ul><\/li> \n <\/ul> \n
Pattern Matching and Case Classes<\/h2> \n \n - \u53ef\u5bf9\u4efb\u4f55\u7c7b\u578b\u8fdb\u884c\u6a21\u5f0f\u5339\u914d\uff0c\u5339\u914d\u987a\u5e8f\u4ece\u4e0a\u81f3\u4e0b<\/li> \n
- \u6a21\u5f0f\u5339\u914d\u4ee3\u66ff
switch<\/code>\uff0c\u9ed8\u8ba4\u5206\u652f\u4e3a case _<\/code>\uff1b\u53ef\u907f\u514d switch<\/code> \u8bed\u53e5\u4e2d\u56e0\u7f3a\u5c11 break<\/code> \u5e26\u6765\u7684 fall-through<\/code> \u95ee\u9898<\/li> \n - \u6a21\u5f0f\u5339\u914d\u4e5f\u662f\u8868\u8fbe\u5f0f\uff0c\u53ef\u5c06\u5176\u8fd4\u56de\u503c\u76f4\u63a5\u8d4b\u503c\u7ed9\u53d8\u91cf<\/li> \n
- \u6a21\u5f0f\u5b88\u536b \/ guards\uff0c\u4e3a\u5339\u914d\u8bbe\u7f6e\u6761\u4ef6\uff0c\u4efb\u4f55
Boolean<\/code> \u6761\u4ef6\u90fd\u53ef\u4f5c\u4e3a\u6a21\u5f0f\u5b88\u536b\uff1bcase ... if ... => ...<\/code><\/li> \n case<\/code> \u5173\u952e\u5b57\u540e\u63a5\u53d8\u91cf\u540d\u6216\u5bf9\u5e94\u6570\u636e\u7ed3\u6784\u4e2d\u4f7f\u7528\u53d8\u91cf\u540d\uff0c\u90a3\u4e48\u5339\u914d\u9879\u5c31\u8d4b\u503c\u7ed9\u8be5\u53d8\u91cf\uff0c\u53d8\u91cf\u540d\u5fc5\u987b\u4ee5\u5c0f\u5199\u5b57\u6bcd\u5f00\u5934<\/strong><\/li> \n - \u4f7f\u7528
|<\/code> \u5206\u9694\u540c\u4e00\u5339\u914d\u7684\u591a\u4e2a\u53ef\u9009\u9879\uff0c\u6b64\u65f6\u4e0d\u53ef\u4f7f\u7528\u53d8\u91cf\u7ed1\u5b9a\u5143\u7d20<\/strong><\/li> \n - \u7c7b\u578b\u5339\u914d\uff0c\u4ee3\u66ff
isInstanceOf<\/code> \u548c asInstanceOf<\/code>\uff0c\u76f4\u63a5\u8fdb\u884c\u7c7b\u578b\u8f6c\u6362 \n \n - \u5fc5\u987b\u4e3a\u7c7b\u578b\u6307\u5b9a\u53d8\u91cf\u540d\uff0c\u5426\u5219\u5339\u914d\u7684\u662f\u5b9e\u9645\u7684\u7c7b\u578b\u5bf9\u8c61<\/li> \n
- \u5339\u914d\u5728\u8fd0\u884c\u65f6\u53d1\u751f\uff0c\u800c JVM \u6cdb\u578b\u4f1a\u88ab\u64e6\u9664 \n
\n - \u4e0d\u53ef\u4ee5\u5339\u914d\u5177\u4f53\u7684
Map<\/code> \u7c7b\u578b\uff08\u53ef\u4f7f\u7528 case Map[_, _]<\/code>\uff0c\u4e0d\u53ef\u4f7f\u7528 case Map[Int, Int]<\/code>\uff09<\/li> \n Array<\/code> \u7684\u7c7b\u578b\u4e0d\u4f1a\u88ab\u64e6\u9664<\/li> \n <\/ul><\/li> \n <\/ul><\/li> \n - \u89e3\u6784 destructuring \n
\n \u5339\u914d\u6570\u7ec4<\/p>
case Array(x, y) => s"$x $y" \/\/ \u5339\u914d\u957f\u5ea6\u4e3a2\u7684\u6570\u7ec4\uff0c\u5e76\u5c06\u5206\u522b\u7ed1\u5b9a\u5230 x, y\ncase Array(0, rest @ _*) => rest.min \/\/ \u53ef\u53d8\u53c2\u6570<\/code><\/pre><\/li> \n \u5339\u914d List<\/code><\/p> case x :: y :: Nil => ... \/\/ \u7ed1\u5b9a\u53c2\u6570\ncase head :: tail => ... \/\/ \u89e3\u6784 head , tail<\/code><\/pre><\/li> \n \u5339\u914d\u5143\u7ec4<\/p>
case (0, _) => ... \/\/ \u5339\u914d\u7b2c\u4e00\u4e2a\u5143\u7d20\u4e3a0\ncase (x, y) => ... \/\/ \u7ed1\u5b9a\u53c2\u6570<\/code><\/pre><\/li> \n <\/ul><\/li> \n - \u5b9a\u4e49\u53d8\u91cf\uff0c\u6ce8\u610f\u4e00\u5b9a\u8981\u5c0f\u5199\u5f00\u5934<\/strong>\uff1b\u5176\u5b9e\u7b49\u4ef7\u4e8e
match<\/code> \u6a21\u5f0f\u5339\u914d\u52a0\u4e0a\u8d4b\u503c\u64cd\u4f5c \n \n val (x, y) = (1, 2)<\/code><\/li> \n val Array(f, s, rest @ _*) = arr<\/code><\/li> \n <\/ul><\/li> \n \u7528\u4e8e for<\/code> \u5faa\u73af\u904d\u5386\u96c6\u5408\uff0c\u5339\u914d\u7b26\u5408\u6761\u4ef6\u7684\u5143\u7d20<\/p> for ((k, v) <- System.getProperties()) println(s"$k $v")\n\/\/ \u5339\u914d value \u4e3a "" \u7684\u9879\uff0c\u5176\u4ed6\u7684\u5219\u88ab\u5ffd\u7565\nfor ((k, "") <- System.getProperties()) println(k)\n\/\/ if guard \u8fc7\u6ee4\nfor ((k, v) <- System.getProperties() if v == "") println(k)<\/code><\/pre><\/li> \n - Case Class \n
\n - \u7528\u4e8e\u6a21\u5f0f\u5339\u914d\u7684\u7279\u6b8a\u7c7b<\/li> \n
- \u6784\u9020\u53c2\u6570\u9ed8\u8ba4\u4e3a
val<\/code>\uff0c\u9ed8\u8ba4\u63d0\u4f9b apply<\/code>\u3001unapply<\/code>\u3001toString<\/code>\u3001equals<\/code>\u3001hashCode<\/code>\u3001copy<\/code> \n \n copy<\/code> \u7528\u4e8e\u590d\u5236\u5bf9\u8c61\u65f6\uff0c\u53ef\u4f7f\u7528\u547d\u540d\u53c2\u6570\u6765\u4fee\u6539\u5c5e\u6027<\/li> \n <\/ul><\/li> \n case class X<\/code> \u4f7f\u7528\u65f6 case X() => ...<\/code>\uff0c\u9700\u8981\u62ec\u53f7<\/li> \n case object S<\/code> \u5355\u4f8b\uff0c\u4f7f\u7528\u65f6 case S => ...<\/code>\uff0c \u4e0d\u8981\u62ec\u53f7<\/li> \n ::<\/code> \u4e5f\u662f case class\uff0c\u914d\u5408\u4e2d\u7f00\u8868\u8fbe\u5f0f\uff0c\u5c31\u662f\u5e38\u89c1\u7684\u5339\u914d\u65b9\u5f0f\uff0ccase head :: tail<\/code>\uff0c\u5b9e\u9645\u8c03\u7528 ::(head, tail)<\/code><\/li> \n - \u53ef\u7528\u4e8e\u5d4c\u5957\u7684\u7ed3\u6784\uff1b\u7ed1\u5b9a\u53d8\u91cf\u3001\u53ef\u53d8\u53c2\u6570\u5339\u914d\u7c7b\u4f3c<\/li> \n
- \u9002\u7528\u4e8e\u56fa\u5b9a\u7ed3\u6784\u7684\u7c7b\uff0c\u5982
List<\/code> \u7b49<\/li> \n <\/ul><\/li> \n sealed<\/code> \u5bc6\u5c01\u7684 \n \n - \u88ab\u4fee\u9970\u7684\u7c7b\uff0c\u5219\u5176\u5b50\u7c7b\u5fc5\u987b\u548c\u8be5\u7c7b\u5728\u540c\u4e00\u4e2a\u6587\u4ef6\u4e2d\u5b9a\u4e49<\/li> \n
- \u5728\u7f16\u8bd1\u65f6\u5373\u786e\u5b9a\u4e86\u6240\u6709\u5339\u914d\u9879\u7684\u53ef\u80fd\u6027<\/li> \n <\/ul><\/li> \n
Option<\/code> \u4e5f\u662f\u4f7f\u7528 case class \u6765\u8868\u793a\u662f\u5426\u6709\u503c\u5b58\u5728\u7684 \n \n - \u5b50\u7c7b
Some<\/code> \u5c01\u88c5\u503c\uff0c\u5b50\u7c7b None<\/code> \u8868\u793a\u65e0\u503c<\/li> \n - \u76f8\u6bd4\u4f7f\u7528
""<\/code> \u6216 null<\/code> \u66f4\u52a0\u5b89\u5168<\/li> \n Map<\/code> \u8fdb\u884c get<\/code> \u64cd\u4f5c\u8fd4\u56de\u7684\u4e5f\u662f Option<\/code>\uff0c\u4e5f\u53ef\u4f7f\u7528\u6a21\u5f0f\u5339\u914d\u6765\u5904\u7406<\/li> \n getOrElse<\/code> \u5c1d\u8bd5\u83b7\u53d6\u503c\uff0c\u672a\u83b7\u53d6\u5230\u5219\u4f7f\u7528\u7ed9\u5b9a\u7684\u503c<\/li> \n <\/ul><\/li> \n - Partial Function \u504f\u51fd\u6570 \n
\n - \u6ca1\u6709\u5bf9\u6240\u6709\u8f93\u5165\u8fdb\u884c\u5b9a\u4e49\u7684\u51fd\u6570<\/li> \n
apply<\/code> \u4ece\u6a21\u5f0f\u5339\u914d\u4e2d\u8ba1\u7b97\u51fd\u6570\u503c\uff0cisDefinedAt<\/code> \u5224\u65ad\u8f93\u5165\u662f\u5426\u5339\u914d\u5b9a\u4e49\u7684\u6a21\u5f0f<\/li> \n case<\/code> \u8bed\u53e5\u5757\u662f\u504f\u51fd\u6570<\/li> \n PartialFunction[A, B]<\/code> \u7684\u5b9e\u4f8b\uff0c A<\/code> \u4e3a\u8f93\u5165\u7c7b\u578b\uff0cB<\/code> \u4e3a\u8f93\u51fa\u7c7b\u578b \n \n - \u53ef\u4f7f\u7528\u504f\u51fd\u6570\u7684
lift<\/code> \u65b9\u6cd5\uff0c\u5c06\u504f\u51fd\u6570\u53d8\u4e3a\u5e38\u89c4\u51fd\u6570\uff0c\u8fd4\u56de\u503c\u4e3a Option[B]<\/code><\/li> \n - \u4e5f\u53ef\u4ee5\u901a\u8fc7
Function.unlift<\/code> \u5c06\u8fd4\u56de Option[B]<\/code> \u7684\u51fd\u6570\u53d8\u4e3a\u504f\u51fd\u6570<\/li> \n <\/ul><\/li> \n Seq[A]<\/code> \u4e5f\u662f\u504f\u51fd\u6570 PartialFunction[Int, A]<\/code><\/li> \n Map[K, V]<\/code> \u4e5f\u662f\u504f\u51fd\u6570 PartialFunction[K, V]<\/code><\/li> \n catch<\/code> \u8bed\u53e5\u4e5f\u662f\u504f\u51fd\u6570\uff0c\u53ef\u5728 catch<\/code> \u5757\u4e2d\u4f7f\u7528\u6a21\u5f0f\u5339\u914d\u5904\u7406\u5f02\u5e38<\/li> \n <\/ul><\/li> \n <\/ul> \n \u6ce8\u89e3<\/h2> \n \n - Scala \u4e2d\u6ce8\u89e3\u53ef\u5f71\u54cd\u4ee3\u7801\u7f16\u8bd1\uff0c\u5982
@BeanProperty<\/code> \u4f1a\u81ea\u52a8\u751f\u6210 getter\/setter<\/code><\/li> \n - \u53ef\u7528\u4e8e \u7c7b\u3001\u65b9\u6cd5\u3001\u5b57\u6bb5\u3001\u53d8\u91cf\u3001\u53c2\u6570\u7b49 \n
\n - \u591a\u4e2a\u6ce8\u89e3\u65e0\u987a\u5e8f<\/li> \n
- \u4e3b\u6784\u9020\u5668\u7684\u6ce8\u89e3\uff0c\u9700\u8981\u52a0\u62ec\u53f7
class Credential @Inject() (var username: String, var password: String)<\/code><\/li> \n - \u8868\u8fbe\u5f0f\u7684\u6ce8\u89e3\uff0c\u4f7f\u7528\u5206\u53f7\u52a0\u6ce8\u89e3\u7684\u65b9\u5f0f
(map.get(key): @unchecked) ...<\/code><\/li> \n - \u7c7b\u578b\u53c2\u6570\u7684\u6ce8\u89e3\uff0c
class Test[@specialized T]<\/code><\/li> \n - \u5b9e\u9645\u7c7b\u578b\u7684\u6ce8\u89e3\uff0c\u653e\u5728\u7c7b\u578b\u4e4b\u540e\uff0c
def name: String @Localized<\/code><\/li> \n <\/ul><\/li> \n - \u6ce8\u89e3\u5b9e\u73b0 \n
\n - \u6ce8\u89e3\u5fc5\u987b\u7ee7\u627f
Annotation<\/code><\/li> \n - \u7c7b\u578b\u6ce8\u89e3\u5fc5\u987b\u7ee7\u627f
TypeAnnotation<\/code><\/li> \n - \u5143\u6ce8\u89e3
@param<\/code>, @field<\/code>, @getter<\/code>, @setter<\/code>, @beanGetter<\/code>, @beanSetter<\/code><\/li> \n <\/ul><\/li> \n - \u5bf9\u5e94 Java \u4fee\u9970\u7b26\u3001\u6807\u8bb0\u63a5\u53e3 \n
\n @volatile<\/code> \u5bf9\u5e94 volatile<\/code> \u5173\u952e\u5b57<\/li> \n @transient<\/code> \u5bf9\u5e94 transient<\/code> \u5173\u952e\u5b57<\/li> \n @strictfp<\/code> \u5bf9\u5e94 strictfp<\/code> \u5173\u952e\u5b57<\/li> \n @native<\/code> \u5bf9\u5e94 native<\/code> \u5173\u952e\u5b57<\/li> \n @cloneable<\/code> \u5bf9\u5e94 Cloneable<\/code><\/li> \n @remote<\/code> \u5bf9\u5e94 java<\/a>.rmi.Remote<\/code><\/li> \n @SerialVersionUID<\/code> \u4ee3\u66ff\u5e8f\u5217\u5316\u5b57\u6bb5<\/li> \n <\/ul><\/li> \n - \u4f7f\u7528
@throws(classOf[Exception])<\/code> \u6765\u5904\u7406 Java \u4e2d\u7684\u53d7\u68c0\u5f02\u5e38<\/li> \n @varargs<\/code> \u5904\u7406\u53ef\u53d8\u53c2\u6570 \n \n @varargs def name(args: String*)<\/code> \u751f\u6210 void name(String... args)<\/code><\/li> \n - \u6ca1\u6709
@varargs<\/code> \u5219\u53ef\u53d8\u53c2\u6570\u4f1a\u88ab\u8f6c\u6362\u6210 Seq[T]<\/code><\/li> \n <\/ul><\/li> \n - \u4f18\u5316 \n
\n @tailrec<\/code> \u4f1a\u5c1d\u8bd5\u4f18\u5316\u5c3e\u9012\u5f52\u8c03\u7528\uff0c\u5c06\u5176\u53d8\u4e3a\u5faa\u73af<\/li> \n @switch<\/code> \u7f16\u8bd1\u5668\u4f1a\u68c0\u67e5 match<\/code> \u8868\u8fbe\u5f0f\u662f","orderid":"0","title":"Scala Class etc. 2(\u4e00)","smalltitle":"","mid":"0","fname":"Scala","special_id":"0","bak_id":"0","info":"0","hits":"294","pages":"2","comments":"0","posttime":"2019-10-09 20:01:14","list":"1570622474","username":"admin","author":"","copyfrom":"","copyfromurl":"","titlecolor":"","fonttype":"0","titleicon":"0","picurl":"https:\/\/www.cppentry.com\/upload_files\/","ispic":"0","yz":"1","yzer":"","yztime":"0","levels":"0","levelstime":"0","keywords":"Scala<\/A> Class<\/A> etc.<\/A>","jumpurl":"","iframeurl":"","style":"","template":"a:3:{s:4:\"head\";s:0:\"\";s:4:\"foot\";s:0:\"\";s:8:\"bencandy\";s:0:\"\";}","target":"0","ip":"14.17.22.32","lastfid":"0","money":"0","buyuser":"","passwd":"","allowdown":"","allowview":"","editer":"","edittime":"0","begintime":"0","endtime":"0","description":"Scala Class etc. 2","lastview":"1713380410","digg_num":"0","digg_time":"0","forbidcomment":"0","ifvote":"0","heart":"","htmlname":"","city_id":"0"},"page":"1"}