「var禁止」禁止

2016/02/20 Hokuriku Comm CampのLTで発表した際のプレゼンテーションスライドです。

1. ʮvarېࢭʯېࢭ @RyotaMurohoshi 2016/02/20(౔)(Hokuriku(ComCamp(2016(powered(by(MVPs
2. C#Λॻ͍͍ͯͯɺ͜Μͳ͜ͱ ݴΘΕͨ͜ͱͳ͍Ͱ͔͢ʁ
3. ʮvar࢖͏ͷېࢭͳʂʯ
4. ࣗݾ঺հ @RyotaMurohoshiͰ͢
5. ઍ༿ݝദࢢ͔Β͖·ͨ͠
6. ࣮Ո͸৽ׁݝͰ͢
7. UnityΫϥελ͔Β͖·ͨ͠
8. Ξϯέʔτʂ
9. C#er%!? ΍ͬͨ͜ͱ͋Δਓʂʁ
10. ʮvarʯ͕Կ͔Θ͔Δ$!? C#erͳΒΘ͔ΔΑͶʂʁ
11. Java΋ॻ͘Αͬͯͻͱ$!?
12. ʮvarېࢭʯݴΘΕͨ͜ͱ͋Δ$!? ͭΒ͍orz
13. ͋Γ͕ͱ͏͍͟͝·ͨ͠
14. C#ͷศརͳݴޠػೳͷʮvarʯ ੈͷதʹ͸ɺͦΕΛݏ͏ɾ࢖Θͳ͍ਓ͕͍ΔΒ͍͠Ͱ͢
15. ͦΕΛ࢖Θͳ͍ͳΜͯͱΜͰ΋ͳ͍
16. ʮvarʯͪΌΜͱ࢖͓͏ͥ
17. ʮvarېࢭʯېࢭ
18. ͦΕͰ͸ʮvarېࢭʯͬͯݴΘΕͨ࣌ͷ ͍͍ײ͡ͷฦ͠Λߟ͍͖͑ͯ·͠ΐ͏ʂ
19. έʔε1 ʮvarɺܕ͕ͳͯ͘ΩϞ͍͔Βېࢭͳʂʯ ͬͯݴΘΕΔ
20. έʔε1ͷݪҼ varΛͪΌΜͱཧղ͍ͯ͠ͳ͍
21. ʮvarͱ͸ʁʯ ҉໧తʹܕࢦఆ͞ΕΔϩʔΧϧม਺ from%MSDN%h+ps:/ /msdn.microso5.com/ja8jp/library/bb384061.aspx
22. ҉໧తʹܕࢦఆ͞ΕΔϩʔΧϧม਺
23. varɺܕ͸͋Γ·͢ʂ ໌ࣔతʹม਺ͷܕΛॻ͔ͳ͍͚ͩʂ
24. // ໌ࣔతʹม਺ͷܕΛॻ͍͍ͯΔ string name = "RyotaMurohoshi"; // =ͷӈล͕จࣈྻϦςϥϧ͔ͩΒstringܕ var title = "ʮvarېࢭʯېࢭ";
25. varɺ୹͔͚ͯ͘ૉఢ΍Μʂ // ΞϗΈ͍ͨʹ௕͍ܕ໊(ۃ୺)Λ2ճॻ͘ʂʁ Dictionary<HogeFuga, List<PiyoPiyoPiyo>> dictionary = new Dictionary<HogeFuga, List<PiyoPiyoPiyo>>(); // 1ճॻ͚͹͍͍ΑͶ var dictionary = new Dictionary<HogeFuga, List<PiyoPiyoPiyo>>(); Θ͟Θ͟ಉ͜͡ͱɺ2ճॻ͘ඞཁͳ͍ΑͶ
26. έʔε1·ͱΊ varʹ͸ܕ͕͋Δɺ໌ࣔతʹͳͬͯͳ͍͚ͩͰɻ ʮvarɺܕ͕ͳͯ͘ΩϞ͍͔Βېࢭͳʂʯͬͯ ݴΘΕͨ৔߹ɺ૬ख͸varΛצҧ͍͍ͯ͠Δ͔Βڭ͑ͯ͋͛Α͏ʂ
27. ͖ͭͮ·ͯ͠...
28. έʔε2 ʮvarɺԿͷܕ͔෼͔Γʹ͍͔͘Βېࢭͳʂʯ ͬͯݴΘΕΔ
29. έʔε2ͷݪҼ varͷཚ༻ɻద੾ʹvarΛ࢖͍ͬͯͳ͍ͨΊɻ
30. (Զ͕ࢥ͏)#varͷྑ͘ͳ͍ར༻ྫ ʮͳΜͩΑɺ͜ͷϝιουͷฦΓ஋ͷܕʯͬͯͳΔʂ ɹ var result = GetResults();
31. varͷཚ༻orz
32. varΛ࢖ͬͯ΋ܕ͕Θ͔Δ࣌ʹɺ varΛ࢖͓͏ʂ
33. (Զ͕ࢥ͏)#varͷྑ͍ར༻ྫ // =ͷӈล͕Ϧςϥϧ var level = 27; var name = "Ryota"; // =ͷӈล͕ίϯετϥΫλ or ϑΝΫτϦϝιου var playerData = new PlayerData(level, name); // =ͷӈล͕δΣωϦοΫϝιουͰܕҾ਺͕ฦΓ஋ܕͳ // ϝδϟʔͳϝιου(࣍ͷ͸UnityͰྑ͘࢖͏΍ͭ) var player = FindObjectOfType<Player>();
34. ʮΘ͟Θ͟ೋճॻ͔ͳͯ͘΋ӈล͔Βܕ͕Θ͔Δ͡ΌΜʯ ͱ͍͏৔߹varͰεοΩϦɻ
35. έʔε2·ͱΊ ʮvarɺԿͷܕ͔෼͔Γʹ͍͔͘Βېࢭͳʂʯͬͯ ͔֬ʹཚ༻͢ΔͱಡΈͮΒ͘ͳΔ͜ͱ΋͋Δɻ ಡΈ΍͘͢ͳΔ৔໘Ͱ͸࢖͏ϧʔϧΛަব͠·͠ΐ͏ʂ
36. ͖ͭͮ·ͯ͠...
37. έʔε3 ʮvarɺList<string>͕IList<string>ʹ ͳͬͯ͘Εͳ͍͔Βېࢭͳʯ ͬͯݴΘΕͨ
38. έʔε3ͷݪҼ JavaͰͷܦݧ͕ཧ༝ʢ͔΋ʁʣ ͜ͷύλʔϯ͕Ұ൪໽հ
39. varͷӈล͕List<string>ܕ͔ͩΒɺlistͷܕ͸List<string>ʹɻ ɹ var list = new List<string>();
40. ࠓ͔ΒνϣοτJavaͷ࿩
41. JavaͷίʔυͰ͢ // Լهͷॻ͖ํ͸ྑ͘ͳ͍ ArrayList<String> list = new ArrayList<String>(); // Լهͷॻ͖ํΛ͢΂͖ List<String> list = new ArrayList<String>(); // μΠϠϞϯυԋࢉࢠͰ୹͔͚͘Δ List<String> list = new ArrayList<>();
42. JavaͰ͸μΠϠϞϯυԋࢉࢠΛ͔͍ͭɺهड़Λলུͭͭ͠ ʮϩʔΧϧม਺ʯΛந৅తͳܕͰѻ͏͜ͱ͕Ͱ͖Δ
43. ͜Εʹ׳Εͨਓ͸͜͏ࢥ͏৔߹͕͋ΔΈ͍ͨ ʮvarɺList<string>͕IList<string>ʹ ͳͬͯ͘Εͳ͍͔Βېࢭͳʯ
44. Java͸ɺμΠϠϞϯυԋࢉࢠͰهड़Λলུͭͭ͠ListΠϯλʔϑΣʔεܕͷม਺Ͱѻ͑Δ // Java List<String> list = new ArrayList<>(); C#ͷvarͷ৔߹ɺIList<string>ΠϯλʔϑΣʔεʹ͸ͳΒͳ͍ɻList<string>ΫϥεʹͳΔɻ // C# var list = new List<string>();
45. ͔֬ʹϝιουͷҾ਺΍ฦΓ஋ͷܕΛ ద੾ʹந৅తͳܕͰѻ͏ͷ͸େ੾ // ྑ͘ͳ͍ྫ(Java) public ArrayList<string> loadList(){ /*தུ*/ } // վળྫ(Java) public List<string> loadList(){ /*தུ*/ }
46. ͚ΕͲʮvarɺList<string>ΫϥεͷΦϒδΣΫτ͕ IList<string>ΠϯλʔϑΣʔεͷม਺ʹͳΒͳ͍͔Βېࢭʯ ͸ؒҧ͍ͬͯΔͱࢥ͏
47. var͕࢖͑Δͷ͸ ϩʔΧϧม਺͚ͩʂ
48. ϩʔΧϧม਺Λந৅ܕͰѻ͏ͷͦΜͳʹେࣄʁ ઈରඞཁʁ
49. ϩʔΧϧม਺ͳΒείʔϓ͸ด͍ͯͯ͡ɺ ͔͔ͨͩ਺ߦɺ௕ͯ͘΋2,30ߦ
50. varͰ୹͔͚͘Δ͜ͱͱɺ ୹͘ดͨ͡είʔϓͰϩʔΧϧม਺Λந৅తͳܕͰѻ͏͜ͱ Ͳ͕ͬͪେࣄͩΖ͏ʁ
51. varͰ୹͔͚͘Δํ͕ ͍͍ΑͶʂ
52. ΋͔ͨ͠͠Β ʮJavaͰ͜͏͔ͩΒɺC#Ͱ΋͜͏͡Όͳ͖Όμϝʯ ػցతʹ൑அͯ͠Δ͔΋͠Εͳ͍orz
53. ʲ࿬ಓʳʮvarɺList<string>͕IList<string>ʹͳͬͯ͘Εͳ͍͔Βېࢭͳʯ͍ͬͯ͏ਓ΍͹ͦ͏ʲภݟʳ ഑ྻ΋IList<T>࣮૷͍ͯ͠Δͷ஌Βͳͦ͏ɻ IReadOnlyList<T>ͱ͔࢖͑͹͍͍ͷʹ஌Βͳͦ͏ɻ
54. έʔε3·ͱΊ ʮvarɺList<string>͕IList<string>ʹͳͬͯ͘Εͳ͍͔Βېࢭͳʯ ͱݴΘΕͨΒɺϩʔΧϧม਺Ͱந৅తͳܕͰѻ͏ϝϦοτͱ ୹͘هड़Ͱ͖Δ͜ͱͷϝϦοτɺͲͪΒ͕େࣄ͔࿩͠߹͓͏ɻ ͦͯ͠উͯʂࠓॻ͍ͯΜͷ͸Java͡Όͳͯ͘C#ͩʂ
55. ࠷ޙʹ • ࠓ೤͍ɺKotlin΍Swi*Ͱ΋var!(ͱ͔valͱ͔let) • varɺ࢖͓͏ͥ • varɺద੾ʹਖ਼͘͠࢖͓͏ͥʂཚ༻͸μϝͳʂ • ʮvarېࢭʯېࢭͳʂʂʂ
56. ʮvarېࢭʯېࢭ @RyotaMurohoshi 2016/02/20(౔)(Hokuriku(ComCamp(2016(powered(by(MVPs
57. ิ଍
58. ͦͷ4 ʮvar࢖͏ͱΠϯλʔϑΣʔεܕͷม਺ʹͳΒͳ͍͔Β ໌ࣔతͳ࣮૷͍ͯ͠Δϝιουݺ΂ͳ͘ͳΔ͡ΌΜʯ ͬͯݴΘΕͨΒʁ
59. ͦ΋ͦ΋͞ɺΫϥε͕Θ͔͍ͬͯΔͷʹ ΠϯλʔϑΣʔεͷ໌ࣔత࣮૷͍ͯ͠Δϝιου ݺͿඞཁ͋Δͷʁ