[B! Java][Generics] raimon49ã®ãƒ–ãƒƒã‚¯ãƒžãƒ¼ã‚¯

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Javaã¨Genericsã«é–¢ã™ã‚‹raimon49ã®ãƒ–ãƒƒã‚¯ãƒžãƒ¼ã‚¯ (7)

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Javaç·ç§°åž‹ã®ãƒ¯ã‚¤ãƒ«ãƒ‰ã‚«ãƒ¼ãƒ‰ã‚’ä¸Šæ‰‹ã«ä½¿ã„ã“ãªã™ãŸã‚ã®å‹˜æ‰€ - é”äººãƒ—ãƒã‚°ãƒ©ãƒžãƒ¼ã‚’ç›®æŒ‡ã—ã¦
Java5ä»¥é™ã§ã¯ç·ç§°åž‹ï¼ˆgenericsï¼‰ãŒJavaè¨€èªžã«å°Žå…¥ã•ã‚Œã¦ã„ã¾ã™ã€‚ç·ç§°åž‹è‡ªä½“ã¯ã€æœ€è¿‘ã®é™çš„ãªåž‹ä»˜ã‘ã®ãƒ—ãƒã‚°ãƒ©ãƒŸãƒ³ã‚°è¨€èªžã§çã—ã„ã“ã¨ã§ã¯ãªãã€ç¾åœ¨ã®æœ€æ–°ç‰ˆã§ã¯.NETã®C#ã‚„Visual Basicã«ã‚‚å°Žå…¥ã•ã‚Œã¦ã„ã¾ã™ã€‚ä¸€èˆ¬çš„ã«ã¯ç·ç§°åž‹ã‚’ã‚µãƒãƒ¼ãƒˆã™ã‚‹ã‚¯ãƒ©ã‚¹ãƒ©ã‚¤ãƒ–ãƒ©ãƒªã‚’è‡ªåˆ†ã§æ£ã—ãå®šç¾©ã™ã‚‹ã“ã¨ã¯éžå¸¸ã«ã‚¹ã‚ãƒ«ãŒã„ã‚‹ãŒã€äº‹å‰ã«å®šç¾©ã•ã‚ŒãŸã‚¯ãƒ©ã‚¹ã‚’ä½¿ã†ã ã‘ã§ã‚ã‚Œã°ã€ãã‚Œã»ã©é›£ã—ããªã„ã¨ã•ã‚Œã¦ã„ã¾ã™ã€‚ã—ã‹ã—ã€Javaè¨€èªžã®ç·ç§°åž‹ã¯æœ¬ã‚¨ãƒ³ãƒˆãƒªã§èª¬æ˜Žã™ã‚‹ã‚ˆã†ã«ç‰¹æ®Šãªã¨ã“ã‚ãŒã‚ã‚Šã€å˜ã«åˆ©ç”¨ã™ã‚‹ã ã‘ã§ã‚‚ä»–ã®è¨€èªžã«æ¯”ã¹ã¦é¥ã‹ã«é›£ã—ã„ã¨ã“ã‚ãŒã‚ã‚‹ã¨ã„ã†ã®ã‚‚äº‹å®Ÿã§ã™ã€‚ç‰¹ã«ç·ç§°åž‹ã‚’ãƒ‘ãƒ©ãƒ¡ãƒ¼ã‚¿åŒ–ã™ã‚‹éš›ã«æŒ‡å®šã™ã‚‹ãƒ¯ã‚¤ãƒ«ãƒ‰ã‚«ãƒ¼ãƒ‰åž‹ï¼ˆList<? extends Serializable>ãªã©)ã®æ„å‘³ã‚’æ£ã—ãç†è§£ã—ã¦ä½¿ã„ã“ãªã™ã“ã¨ã¯ç°¡å˜ãªã“ã¨ã§ã¯ã‚ã‚Šã¾ã›ã‚“ã€‚ãã®çµæžœã€æ˜”ã®JDK1.4ã¾ã§ã®ã‚ˆã†ã«åž‹ãƒ‘ãƒ©ãƒ¡ãƒ¼ã‚¿ãƒ¼ã®ãªã„
raimon49 2011/04/15
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https://ryoasai.hatenadiary.org/entry/20110321/1300696942
raimon49 2011/03/21
Java

Generics

programming

study
ãƒªãƒ³ã‚¯
Javaè¨€èªžã§å›ºå®šè¦ç´ ã®Listã‚’åˆæœŸåŒ–ã™ã‚‹éš›ã®ã‚¤ãƒ‡ã‚£ã‚ªãƒ - é”äººãƒ—ãƒã‚°ãƒ©ãƒžãƒ¼ã‚’ç›®æŒ‡ã—ã¦
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raimon49 2011/01/10
Arrays.asList

Java

Generics

programming
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Javaã¨Scalaã¨C#ã®ã‚¸ã‚§ãƒãƒªã‚¯ã‚¹æ©Ÿèƒ½æ¯”è¼ƒè¡¨ - Onioné–‹ç™ºã—ã¤ã¤ã€PEGEXã‚’é–‹ç™ºã™ã‚‹æ—¥è¨˜
Javaã¨Scalaã¨C#ã®ã‚¸ã‚§ãƒãƒªã‚¯ã‚¹ã¯ã€ã„ãšã‚Œã‚‚ç¶™æ‰¿ã‚’æŒã£ãŸã‚ªãƒ–ã‚¸ã‚§ã‚¯ãƒˆæŒ‡å‘è¨€èªžã«ãŠã„ã¦Parametric Polymorphismã‚’å®Ÿç¾ã™ã‚‹ãŸã‚ã®æ‰‹æ®µã§ã‚ã‚Šã€ãã‚Œãžã‚Œç•°ãªã£ãŸç‰¹æ€§ã‚’æŒã£ã¦ã„ã‚‹ã€‚ã¨ã„ã†ã‚ã‘ã§ã€ãã‚Œãžã‚Œã®è¨€èªžã«ãŠã„ã¦ã‚¸ã‚§ãƒãƒªã‚¯ã‚¹ãŒã©ã®ã‚ˆã†ã«ã‚µãƒãƒ¼ãƒˆã•ã‚Œã¦ã„ã‚‹ã‹ã‚’æ¯”è¼ƒã—ãŸè¡¨ã‚’ç”¨æ„ã—ã¦ã¿ãŸã€‚å¾Œã§æ°—ãŒå‘ã„ãŸã‚‰ã€å„é …ç›®ã®èª¬æ˜Žã‚’è¿½åŠ ã™ã‚‹ã‹ã‚‚ã€‚ Java(5.0ä»¥é™) Scala C#(4.0) ã‚¸ã‚§ãƒãƒªãƒƒã‚¯ãªã‚¯ãƒ©ã‚¹ â—‹ â—‹ â—‹ ã‚¸ã‚§ãƒãƒªãƒƒã‚¯ãªãƒ¡ã‚½ãƒƒãƒ‰ â—‹ â—‹ â—‹ åž‹ãƒ‘ãƒ©ãƒ¡ãƒ¼ã‚¿ã®ä¸Šé™ â—‹ â—‹ â—‹ åž‹ãƒ‘ãƒ©ãƒ¡ãƒ¼ã‚¿ã®ä¸‹é™ Ã— â—‹ Ã— åž‹ãƒ‘ãƒ©ãƒ¡ãƒ¼ã‚¿ã®æŽ¨è«– â—‹ â—‹ â—‹ å…¨ã¦ã®åž‹ã®ã‚µãƒ–ã‚¿ã‚¤ãƒ—(Scalaã«ãŠã‘ã‚‹Nothing) Ã— â—‹ Ã— definition-site variance Ã— â—‹ â—‹ use-site variance â—‹(Wildcard) â—‹(Existential Typ
raimon49 2010/11/09
Generics

Csharp

Java

Scala
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Javaã®ã‚„ã‚„ã“ã—ã„ã‚¸ã‚§ãƒãƒªã‚¯ã‚¹ã®è©±ã‚’ã—ã‚ˆã†ã€‚*1 å†å¸°çš„ã‚¸ã‚§ãƒãƒªã‚¯ã‚¹ ã‚¯ãƒ©ã‚¹HogeãŒã‚ã£ãŸã¨ã—ã¦ã€åž‹å¤‰æ•°Tã‚’å–ã‚‹ã€‚ public class Hoge<T> {} ã“ã®Hogeã®åž‹å¤‰æ•°TãŒextends Hogeã¨ã™ã‚‹ã¨ public class Hoge<T extends Hoge> {} ã™ã‚‹ã¨ã€T extends Hoge ã® Hoge ãŒ rawåž‹ã ã¨è¦å‘Šã•ã‚Œã‚‹ã€‚Hogeã®<>ã®éƒ¨åˆ†ã«Hogeåž‹ã‚’ç¶™æ‰¿ã—ãŸåž‹ã‚’æŒ‡å®šã—ãªã‘ã‚Œã°ãªã‚‰ãªã„ã€‚ã“ã“ã§åž‹å¤‰æ•°T ãŒ extends Hogeã ã£ãŸã®ã§ã€ä¸åº¦ã„ã„ã‹ã‚‰Tåž‹ã‚’ãŠã•ã‚ã‚ˆã†ã€‚ public class Hoge<T extends Hoge<T>> {} ã“ã‚Œã¯å†å¸°çš„ã‚¸ã‚§ãƒãƒªã‚¯ã‚¹(recursive generics)ã¨å‘¼ã°ã‚Œã¦ã„ã‚‹ã‚ˆã†ã ã€‚ è¿½è¨˜ï¼šåƒ•ã¯å‹æ‰‹ã«è‡ªå·±è¨€åŠåž‹ã‚¸ã‚§ãƒãƒªã‚¯ã‚¹ãªã©ã¨å‘¼ã‚“ã§ã„ãŸã€‚æƒ…å ±ã‚µãƒ³ã‚¯ã‚¹ï¼ä½µã›ã¦ã‚¿ã‚¤ãƒˆãƒ«ãªã©ã‚‚è¡¨ç¾
raimon49 2010/11/02
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ã‚³ãƒ¬ã‚¯ã‚·ãƒ§ãƒ³ã‚’åˆ©ç”¨ã™ã‚‹Tips ã‚¤ãƒ†ãƒ¬ãƒ¼ã‚·ãƒ§ãƒ³ Iteratorã‚’ä½¿ã† ã‚³ãƒ¬ã‚¯ã‚·ãƒ§ãƒ³ã®ä¸ã«æ ¼ç´ã•ã‚ŒãŸè¦ç´ ã«ã‚¢ã‚¯ã‚»ã‚¹ã™ã‚‹æ™‚ã¯ã€Iteratorã‚’ä½¿ç”¨ã™ã‚‹ã“ã¨ãŒé€šä¾‹ã§ã™ã€‚ãã®æ™‚ã®ã‚³ãƒ¼ãƒ‡ã‚£ãƒ³ã‚°ãƒ‘ã‚¿ãƒ¼ãƒ³ã§æœ€ã‚‚å¤šã„æ›¸ãæ–¹ã¯æ¬¡ã®ã‚ˆã†ã«whileæ–‡ã‚’ä½¿ç”¨ã™ã‚‹ã‚‚ã®ã§ã™ã€‚ List persons; : Iterator it = persons.iterator(); while (it.hasNext()) { Person person = (Person)it.next(); // do something for person. } ã—ã‹ã—ã€whileæ–‡ã‚’ä½¿ã†ã¨ã‚¤ãƒ†ãƒ¬ãƒ¼ã‚¿ã‚’ç¤ºã™ãƒãƒ¼ã‚«ãƒ«å¤‰æ•°itã®æœ‰åŠ¹ç¯„å›²ãŒãƒ¡ã‚½ãƒƒãƒ‰å…¨ä½“ã«æ¸¡ã£ã¦ã—ã¾ã„ã¾ã™ã€‚æœ¬æ¥ã¯ã€whileæ–‡ã®å†…å´ã«é–‰ã˜ã¦æ¬²ã—ã„ã¨ã“ã‚ã§ã™ã€‚ã¾ãŸã€è¤‡æ•°ã®ã‚³ãƒ¬ã‚¯ã‚·ãƒ§ãƒ³ã‚’æ“ä½œã™ã‚‹æ™‚ã«ã€ãƒãƒ¼ã‚«ãƒ«å¤‰æ•°åitã‚’å†åº¦ä½¿ã„ãŸã„ã®ã§ã™ãŒã€2åº¦ç›®ã¯å¤‰æ•°ã‚’å®£è¨€ã—ãªã„ã‚ˆã†ã«
raimon49 2009/09/10
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ã‚¸ã‚§ãƒãƒªãƒƒã‚¯: Java vs C#
ï»¿ ã‚¸ã‚§ãƒãƒªãƒƒã‚¯: Java vs C# æ¦‚è¦ 2005 å¹´åˆé ã«å…¬é–‹ã•ã‚ŒãŸ Java è¨€èªžä»•æ§˜ç¬¬ 3 ç‰ˆ (é–‹ç™ºå®Ÿè¡Œç’°å¢ƒã¯ 2004 å¹´ç§‹ã«å…ˆç«‹ã£ã¦å…¬é–‹ã•ã‚Œã¦ã„ãŸ) ã¨ 2005 å¹´ 6 æœˆã« ECMA ã«æ‰¿èªã•ã‚ŒãŸ C# è¨€èªžä»•æ§˜ç¬¬ 3 ç‰ˆ (é–‹ç™ºå®Ÿè¡Œç’°å¢ƒã¯ 2005 å¹´æœ«ã«å…¬é–‹ã•ã‚ŒãŸ) ã§ã¯ã€å…±ã«ã‚¸ã‚§ãƒãƒªãƒƒã‚¯ (ã‚¸ã‚§ãƒãƒªãƒƒã‚¯ã‚¹ã€ã‚¸ã‚§ãƒãƒªã‚¯ã‚¹ã€ç·ç§°: generics) ã¨ã„ã†æ–°ã—ã„æ¦‚å¿µãŒå°Žå…¥ã•ã‚Œã€æ–‡æ³•ã‚‚ãã‚Œã«ä¼´ã£ã¦å¤‰åŒ–ã—ã¦ã„ã‚‹ã€‚ Java ã¨ C# ã¯ã©ã¡ã‚‰ã‚‚é™çš„ãªåž‹ä»˜ã‘ã‚’è¡Œã†ã‚ªãƒ–ã‚¸ã‚§ã‚¯ãƒˆæŒ‡å‘ãƒ—ãƒã‚°ãƒ©ãƒŸãƒ³ã‚°è¨€èªžã§ã‚ã‚Šã€C è¨€èªžã‚’åŸºã«ã—ãŸ ä¼¼ãŸã‚ˆã†ãªæ–‡æ³•ã‚’ã—ã¦ã„ã‚‹ã€‚ ã“ã®è¨˜äº‹ã§ã¯ã€Java è¨€èªžã®ã‚¸ã‚§ãƒãƒªãƒƒã‚¯ã¨ C# è¨€èªžã®ã‚¸ã‚§ãƒãƒªãƒƒã‚¯ã‚’ã€ãã®æ©Ÿèƒ½ã‚„æ–‡æ³•ã®é•ã„ã‚’ä¸å¿ƒã«æ¯”è¼ƒã™ã‚‹ã€‚ ã‚¸ã‚§ãƒãƒªãƒƒã‚¯ãªåž‹ ã‚¸ã‚§ãƒãƒªãƒƒã‚¯ãªåž‹ã¯ã€ã©ã¡ã‚‰ã®è¨€èªžã§ã‚‚å±±åž‹ã®æ‹¬å¼§ã‚’ä½¿ã£ã¦è¡¨ã•ã‚Œã‚‹ã€‚ã‚¸ã‚§
raimon49 2009/06/30
ï¼žC# ã§ã¯åŒã˜åå‰ã§ã‚‚åž‹ãƒ‘ãƒ©ãƒ¡ãƒ¼ã‚¿ã®æ•°ãŒç•°ãªã‚‹ãªã‚‰ã°å…¨ãåˆ¥ã®åž‹ã¨ã—ã¦æ‰±ã‚ã‚Œã‚‹ã€‚ã‚†ãˆã«ã€MyClass ã¨ MyClass ã¨ MyClass ã¯åŒã˜åå‰ç©ºé–“å†…ã«å…±å˜ã§ãã‚‹ã€‚ / C#ã¨Javaã«ãŠã‘ã‚‹Genericsã®é•ã„ã€‚C#ã§ã¯ãƒ‘ãƒ©ãƒ¡ãƒ¼ã‚¿é•ã„ã®åž‹å®£è¨€ã‚„ã‚¸ã‚§ãƒ

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Generics

programming
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