Trap Questions in Java and Obj-C

Transcript

1. 4XJGU,PUMJOѪ޷ձ
   7PM
   !(.0ϖύϘ
   

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2. 4XJGUͱ,PUMJO
   

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3. 4XJGUͱ,PUMJO
   

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4. +BWBͱ0CKFDUJWF$
   ͷ࿩Λ͠·͢
   

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5. ͳΜͰࠓ͞Β+BWB0CK$
   

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

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7. Ռͨͯ͠ຊ౰ʹͦ͏ͩΖ͏͔ʁ
   

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

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9. ͱ͍͏͜ͱͰ
   

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

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

    J04 डୗ։ൃ
    ೥൒

    J04 ࣗࣾ։ൃ
    ࠓίί
    w 5XJUUFS 2JJUB@LJ

    (JU)VC,*
    w 4XJGUѪ޷ձࢀՃप೥

    ΋͏΍ΜΧϨʔ͸೥໨
    ͓લ୭Α
    

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12. #VJME$POpHTXJGU
    ελʔ͍ͩ͘͞
    

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

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14. +BWBฤ
    

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15. ୈ໰
    

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16. ࣍ͷίʔυͷಈ͖͸Ͳ͏ͳΔʁ
    

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17. ࣍ͷίʔυͷಈ͖͸Ͳ͏ͳΔʁ
    public class Sample {
    public static void main(String... args) {
    while (false) {
    System.out.println("hoge");
    }
    }
    }
    

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18. ࣍ͷίʔυͷಈ͖͸Ͳ͏ͳΔʁ
    public class Sample {
    public static void main(String... args) {
    while (false) {
    System.out.println("hoge");
    }
    }
    }
    lIPHFz͕ճ͚ͩग़ྗ͞ΕΔ Կ΋ى͖ͳ͍
    ίϯύΠϧΤϥʔ ࣮ߦ࣌Τϥʔ
    

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19. ࣍ͷίʔυͷಈ͖͸Ͳ͏ͳΔʁ
    public class Sample {
    public static void main(String... args) {
    while (false) {
    System.out.println("hoge");
    }
    }
    }
    lIPHFz͕ճ͚ͩग़ྗ͞ΕΔ Կ΋ى͖ͳ͍
    ίϯύΠϧΤϥʔ ࣮ߦ࣌Τϥʔ
    

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20. ղઆ
    public class Sample {
    public static void main(String... args) {
    while (false) {
    System.out.println("hoge");
    }
    }
    } 6OSFBDIBCMFDPEF
    

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21. ୈ໰
    

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22. ୈ໰Λ౿·͑ͯ
    public class Sample {
    public static void main(String... args) {
    while (false) {
    System.out.println("hoge");
    }
    }
    }
    

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23. ࣍ͷίʔυͷಈ͖͸Ͳ͏ͳΔʁ
    public class Sample {
    public static void main(String... args) {
    do {
    System.out.println("hoge");
    } while (false);
    }
    }
    

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24. ࣍ͷίʔυͷಈ͖͸Ͳ͏ͳΔʁ
    public class Sample {
    public static void main(String... args) {
    do {
    System.out.println("hoge");
    } while (false);
    }
    }
    lIPHFz͕ճ͚ͩग़ྗ͞ΕΔ Կ΋ى͖ͳ͍
    ίϯύΠϧΤϥʔ ࣮ߦ࣌Τϥʔ
    

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25. ࣍ͷίʔυͷಈ͖͸Ͳ͏ͳΔʁ
    public class Sample {
    public static void main(String... args) {
    do {
    System.out.println("hoge");
    } while (false);
    }
    }
    lIPHFz͕ճ͚ͩग़ྗ͞ΕΔ Կ΋ى͖ͳ͍
    ίϯύΠϧΤϥʔ ࣮ߦ࣌Τϥʔ
    

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26. public class Sample {
    public static void main(String... args) {
    do {
    System.out.println("hoge");
    } while (false);
    }
    }
    ղઆ
    EPXIJMF͸ࣄޙධՁ ճॲཧͨ͠ޙʹ৚݅ࣜΛ൑ఆ
    
    

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27. ղઆ
    ॲཧ
    ৚
    ݅
    XIJMF
    ॲཧ
    ৚
    ݅
    EPXIJMF
    

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28. 0CKFDUJWF$ฤ
    

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29. ୈ໰
    

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30. Կ͕ग़ྗ͞ΕΔʁ
    

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

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

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

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34. ղઆ
    w @0͸4/VNCFSOVNCFS8JUI*OU>ͷ4ZOUBY4VHBS
    w /4/VNCFS͸ΦϒδΣΫτ
    w ΦϒδΣΫτͱͯ͠͸ଘࡏ͢ΔͨΊɺ

    USVFͱͯ͠൑ఆ͞ΕΔ
    w @NO΋ಉ༷
    

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35. ୈ໰
    

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36. Կ͕ग़ྗ͞ΕΔʁ
    

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37. Կ͕ग़ྗ͞ΕΔʁ
    [
    "hoge",
    "fuga",
    null,
    "foo",
    "bar"
    ]
    TBNQMFKTPO
    NSArray *array = ... // JSONΛಡΈࠐΉॲཧ
    if (array[2]) {
    NSLog(@"true");
    } else {
    NSLog(@"false");
    }
    

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38. Կ͕ग़ྗ͞ΕΔʁ
    USVF GBMTF
    [
    "hoge",
    "fuga",
    null,
    "foo",
    "bar"
    ]
    TBNQMFKTPO
    NSArray *array = ... // JSONΛಡΈࠐΉॲཧ
    if (array[2]) {
    NSLog(@"true");
    } else {
    NSLog(@"false");
    }
    

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39. Կ͕ग़ྗ͞ΕΔʁ
    USVF GBMTF
    [
    "hoge",
    "fuga",
    null,
    "foo",
    "bar"
    ]
    TBNQMFKTPO
    NSArray *array = ... // JSONΛಡΈࠐΉॲཧ
    if (array[2]) {
    NSLog(@"true");
    } else {
    NSLog(@"false");
    }
    

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40. ղઆ
    w /4"SSBZ౳ͷίϨΫγϣϯʹ͸OJMΛೖΕΔ͜ͱ͕Ͱ͖ͳ
    ͍
    w େମखஈͱͯ͠/4/VMMͱ͍͏ΫϥεΛ࢖͏
    w ͜ͷ࣌BSSBZ<>͔ΒऔΓग़͞ΕΔͷ͸4/VMMOVMM>ͱ͍͏
    γϯάϧτϯΦϒδΣΫτ
    w ΦϒδΣΫτͳͷͰUSVFͱͯ͠൑ఆ͞ΕΔ
    

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

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42. ͜ΜͳΜ஌ͬͯͯԿʹͳΔʁ
    

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

    ϨΨγʔͳγεςϜͰۃكʹฆΕࠐΜͰΔ
    w Ϧʔμϒϧίʔυͬͯ஌ͬͯΔʁ
    

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44. ͜ΜͳΜ஌ͬͯͯԿʹͳΔʁ
    w 0CK$
    w ҙ֎ͱݟམͱ͕ͪ͠
    w ͜ͷखͷޡղ͔ΒੜͣΔόά͕࣮ࡍʹ͋ͬͨ
    w 4XJGU΁ͷϦϓϨʔεͰ૝ఆͱҧ͏ಈ͖Λ͢Δͱ͔
    w ಛʹ഑ྻʹฆΕࠐΉOVMM໰୊͸͋Δ͋Δ
    

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45. ͜ΜͳΜ஌ͬͯͯԿʹͳΔʁ
    w ͍ͭͰʹ
    w ৽ਓݚमͰυϠΕΔ
    

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

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47. ྑ͍͓೥Λʂ✋
    

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