Trap Questions in Java and Obj-C

Transcript

1. 4XJGU,PUMJOѪ޷ձ 7PM
   
   !(.0ϖύϘ

2. 4XJGUͱ,PUMJO

3. 4XJGUͱ,PUMJO

4. +BWBͱ0CKFDUJWF$
   ͷ࿩Λ͠·͢

5. ͳΜͰࠓ͞Β+BWB0CK$

6. ͳΜͰࠓ͞Β+BWB0CK$ w ࠓͷ࣌୅ΞϓϦ͸4XJGU,PUMJOͰॻ͘ͷ͕౰ͨΓલ
   w ࠓͲ͖+BWB0CK$ͳΜͯ৮ΒΜ΍Ζ

7. Ռͨͯ͠ຊ౰ʹͦ͏ͩΖ͏͔ʁ

8. Ռͨͯ͠ຊ౰ʹͦ͏ͩΖ͏͔ʁ w 044ϥΠϒϥϦ͸ϦϦʔε͞Εͨ࣌୅΍ϥΠϒϥϦͷಛ ੑ্+BWB0CK$Ͱॻ͔Ε͍ͯΔ΋ͷ΋·ͩ·ͩଟ͍
   w ࣮૷Λ֬ೝͨ͠Γ13Λग़ͨ͠Γ͢ΔͳΒ΍ͬͺΓͦͷล ͷ஌ࣝ͸ඞཁ

9. ͱ͍͏͜ͱͰ

10. ҙ֎ͱҾ͔͔ͬΔʂʁ
    ݴޠ࢓༷ΫΠζ
    +BWB0CKFDUJWF$ฤ

11. w 5BLVIJSP
    .VUB
    BLB
    ௣໊Նر ,*
    w 4&೥
    8FC
    J04
    "OESPJE
    ৽ਓݚमߨࢣFUD

    
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    w 5XJUUFS
    2JJUB
    @LJ
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    ,*
    w 4XJGUѪ޷ձࢀՃप೥
 ΋͏΍ΜΧϨʔ͸೥໨ ͓લ୭Α

12. #VJME$POpHTXJGU
    ελʔ͍ͩ͘͞
    

13. ݴޠ࢓༷ΫΠζ w +BWB
    ໰
    w 0CKFDUJWF$
    ໰

14. +BWBฤ

15. ୈ໰

16. ࣍ͷίʔυͷಈ͖͸Ͳ͏ͳΔʁ

17. ࣍ͷίʔυͷಈ͖͸Ͳ͏ͳΔʁ public class Sample { public static void main(String... args)

    { while (false) { System.out.println("hoge"); } } }

18. ࣍ͷίʔυͷಈ͖͸Ͳ͏ͳΔʁ public class Sample { public static void main(String... args)

    { while (false) { System.out.println("hoge"); } } } 
    lIPHFz͕ճ͚ͩग़ྗ͞ΕΔ 
    Կ΋ى͖ͳ͍ 
    ίϯύΠϧΤϥʔ 
    ࣮ߦ࣌Τϥʔ

19. ࣍ͷίʔυͷಈ͖͸Ͳ͏ͳΔʁ public class Sample { public static void main(String... args)

    { while (false) { System.out.println("hoge"); } } } 
    lIPHFz͕ճ͚ͩग़ྗ͞ΕΔ 
    Կ΋ى͖ͳ͍ 
    ίϯύΠϧΤϥʔ 
    ࣮ߦ࣌Τϥʔ

20. ղઆ public class Sample { public static void main(String... args)

    { while (false) { System.out.println("hoge"); } } } 6OSFBDIBCMF
    DPEF

21. ୈ໰

22. ୈ໰Λ౿·͑ͯ public class Sample { public static void main(String... args)

    { while (false) { System.out.println("hoge"); } } }

23. ࣍ͷίʔυͷಈ͖͸Ͳ͏ͳΔʁ public class Sample { public static void main(String... args)

    { do { System.out.println("hoge"); } while (false); } }

24. ࣍ͷίʔυͷಈ͖͸Ͳ͏ͳΔʁ public class Sample { public static void main(String... args)

    { do { System.out.println("hoge"); } while (false); } } 
    lIPHFz͕ճ͚ͩग़ྗ͞ΕΔ 
    Կ΋ى͖ͳ͍ 
    ίϯύΠϧΤϥʔ 
    ࣮ߦ࣌Τϥʔ

25. ࣍ͷίʔυͷಈ͖͸Ͳ͏ͳΔʁ public class Sample { public static void main(String... args)

    { do { System.out.println("hoge"); } while (false); } } 
    lIPHFz͕ճ͚ͩग़ྗ͞ΕΔ 
    Կ΋ى͖ͳ͍ 
    ίϯύΠϧΤϥʔ 
    ࣮ߦ࣌Τϥʔ

26. public class Sample { public static void main(String... args) {

    do { System.out.println("hoge"); } while (false); } } ղઆ EPXIJMF͸ࣄޙධՁ ճॲཧͨ͠ޙʹ৚݅ࣜΛ൑ఆ

27. ղઆ ॲཧ ৚ ݅ XIJMF ॲཧ ৚ ݅ EPXIJMF

28. 0CKFDUJWF$ฤ

29. ୈ໰

30. Կ͕ग़ྗ͞ΕΔʁ

31. Կ͕ग़ྗ͞ΕΔʁ if (@0) { NSLog(@"true"); } else { NSLog(@"false"); }

32. Կ͕ग़ྗ͞ΕΔʁ if (@0) { NSLog(@"true"); } else { NSLog(@"false"); }

    
    USVF 
    GBMTF

33. Կ͕ग़ྗ͞ΕΔʁ if (@0) { NSLog(@"true"); } else { NSLog(@"false"); }

    
    USVF 
    GBMTF

34. ղઆ w @0͸</4/VNCFS
    OVNCFS8JUI*OU>ͷ4ZOUBY
    4VHBS
    w /4/VNCFS͸ΦϒδΣΫτ
    w ΦϒδΣΫτͱͯ͠͸ଘࡏ͢ΔͨΊɺ
 USVFͱͯ͠൑ఆ͞ΕΔ
    w @NO΋ಉ༷

35. ୈ໰

36. Կ͕ग़ྗ͞ΕΔʁ

37. Կ͕ग़ྗ͞ΕΔʁ [ "hoge", "fuga", null, "foo", "bar" ] TBNQMFKTPO NSArray

    *array = ... // JSONΛಡΈࠐΉॲཧ if (array[2]) { NSLog(@"true"); } else { NSLog(@"false"); }

38. Կ͕ग़ྗ͞ΕΔʁ 
    USVF 
    GBMTF [ "hoge", "fuga", null, "foo", "bar" ]

    TBNQMFKTPO NSArray *array = ... // JSONΛಡΈࠐΉॲཧ if (array[2]) { NSLog(@"true"); } else { NSLog(@"false"); }

39. Կ͕ग़ྗ͞ΕΔʁ 
    USVF 
    GBMTF [ "hoge", "fuga", null, "foo", "bar" ]

    TBNQMFKTPO NSArray *array = ... // JSONΛಡΈࠐΉॲཧ if (array[2]) { NSLog(@"true"); } else { NSLog(@"false"); }

40. ղઆ w /4"SSBZ౳ͷίϨΫγϣϯʹ͸OJMΛೖΕΔ͜ͱ͕Ͱ͖ͳ ͍
    w େମखஈͱͯ͠/4/VMMͱ͍͏ΫϥεΛ࢖͏
    w ͜ͷ࣌BSSBZ<>͔ΒऔΓग़͞ΕΔͷ͸</4/VMM
    OVMM>ͱ͍͏ γϯάϧτϯΦϒδΣΫτ
    w

    ΦϒδΣΫτͳͷͰUSVFͱͯ͠൑ఆ͞ΕΔ

41. /4/VMMͱOJM NSLog(@"%@", nil); // -> (null) NSLog(@"%@", [NSNull null]); //

    -> <null> ഑ྻʹฆΕ͍ͯΔOVMM͸Α͘ݟམͱ͕ͪ͠

42. ͜ΜͳΜ஌ͬͯͯԿʹͳΔʁ

43. ͜ΜͳΜ஌ͬͯͯԿʹͳΔʁ w +BWB
    w 0$+1 0SBDMFೝఆࢿ֨ Ͱ͜͏͍͏໰୊͕ग़୊͞ΕΔ
    w ࣮຿Ͱ࢖͏ҙຯ͸໓ଟʹແ͍͕ɺ
 ϨΨγʔͳγεςϜͰۃكʹฆΕࠐΜͰΔ
    

    w Ϧʔμϒϧίʔυͬͯ஌ͬͯΔʁ

44. ͜ΜͳΜ஌ͬͯͯԿʹͳΔʁ w 0CK$
    w ҙ֎ͱݟམͱ͕ͪ͠
    w ͜ͷखͷޡղ͔ΒੜͣΔόά͕࣮ࡍʹ͋ͬͨ
    w 4XJGU΁ͷϦϓϨʔεͰ૝ఆͱҧ͏ಈ͖Λ͢Δͱ͔
    w

    ಛʹ഑ྻʹฆΕࠐΉOVMM໰୊͸͋Δ͋Δ

45. ͜ΜͳΜ஌ͬͯͯԿʹͳΔʁ w ͍ͭͰʹ
    w ৽ਓݚमͰυϠΕΔ

46. ·ͱΊ w ϨΨγʔݴޠͷཧղ͸ϦϓϨʔεͷڧ͍ຯํ
    w ࢥΘ͵όάΛੜ·ͳ͍ͨΊʹ΋ݴޠ࢓༷ͷཧղ͸େ੾
    w ࣮຿Ͱ࢖Θͳ͍஌͔ࣝͩΒͬͯܰࢹ͠ͳ͍Α͏ʹ

47. ྑ͍͓೥Λʂ✋