SwiftのStringの文字の数え方を完全理解する

SwiftはUnicodeの扱いに非常に長けた言語であり、絵文字を含む文字列でも正しい文字数を計算してくれます。
その反面、Unicodeの複雑さに引きずられてしまい、直感的な操作ができない時もあります。たとえば、 string[2] と書いても3番目の文字を取得することはできません。

そんな複雑なところのあるSwiftの文字列処理ですが、複雑なものを受け入れてきちんと理解するのはそこまで難しいものではありません。

このトークでは、Unicodeとの関係を意識しながら、Swiftの文字数の扱い方とその裏にある考え方を解説します。

Transcript

1. SwiftͷStringͷจࣈͷ
   ਺͑ํΛ׬શཧղ͢Δ
   Takanori Hirobe @taka1068
   

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2. • ኍ෦ وಙ
   
   • ϑΣϯϦϧגࣜձࣾॴଐ
   ࣗݾ঺հ
   

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3. ࣗݾ঺հ
   • ኍ෦ وಙ
   
   • ϑΣϯϦϧגࣜձࣾॴଐ
   ΰʔϧυεϙϯαʔ
   

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4. ࣗݾ঺հ
   • ኍ෦ وಙ
   
   • ϑΣϯϦϧגࣜձࣾॴଐ
   ΰʔϧυεϙϯαʔ
   Ϙτϧ΢Υʔλʔεϙϯαʔ
   

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5. ࣗݾ঺հ
   • ኍ෦ وಙ
   
   • ϑΣϯϦϧגࣜձࣾॴଐ
   ΰʔϧυεϙϯαʔ
   Ϙτϧ΢Υʔλʔεϙϯαʔ
   

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6. ΞδΣϯμ
   - SwiftͷStringʹ͍ͭͯ
   
   - Unicodeʹ͍ͭͯ
   
   - Stringͱཁૉͷஔ͖׵͑ʹ͍ͭͯ
   

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7. ΞδΣϯμ
   -SwiftͷStringʹ͍ͭͯ
   - Unicodeʹ͍ͭͯ
   
   - Stringͱཁૉͷஔ͖׵͑ʹ͍ͭͯ
   

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8. print("Hello, iOSDC!")
   

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9. String
   

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10. String
    Value Type
    Bridges to NSString
    

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11. String
    Value Type
    UTF-8 Encoded
    Hashable
    Bridges to NSString
    

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12. String
    Value Type
    UTF-8 Encoded
    Equatable Hashable
    Bridges to NSString
    Collection
    

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13. String
    Value Type
    UTF-8 Encoded
    Equatable Hashable
    Bridges to NSString
    Collection
    

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14. Collection
    

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15. Collection
    let array = [10, 20, 30, 40, 50]
    let string = "abc͍͋͏͓͑"
    

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16. Collection
    let array = [10, 20, 30, 40, 50]
    let string = "abc͍͋͏͓͑"
    let first = array[0]
    

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17. Collection
    let array = [10, 20, 30, 40, 50]
    let string = "abc͍͋͏͓͑"
    let first = array[0]
    let first = array[array.startIndex]
    or
    better
    

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18. Collection
    let array = [10, 20, 30, 40, 50]
    let string = "abc͍͋͏͓͑"
    let first = array[0]
    

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19. Collection
    let array = [10, 20, 30, 40, 50]
    let string = "abc͍͋͏͓͑"
    let first = array[0]
    Int
    ഑ྻͷཁૉͷܕ
    

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20. Collection
    let array = [10, 20, 30, 40, 50]
    let string = "abc͍͋͏͓͑"
    ఴࣈΞΫηε: Int
    ཁૉͷܕ: Int
    

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21. Collection
    let array = [10, 20, 30, 40, 50]
    let string = "abc͍͋͏͓͑"
    ఴࣈΞΫηε: Int
    ཁૉͷܕ: Int
    let first = string[0]
    

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22. Collection
    let array = [10, 20, 30, 40, 50]
    let string = "abc͍͋͏͓͑"
    ఴࣈΞΫηε: Int
    ཁૉͷܕ: Int
    let first = string[0]
    

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23. Collection
    let array = [10, 20, 30, 40, 50]
    let string = "abc͍͋͏͓͑"
    ఴࣈΞΫηε: Int
    ཁૉͷܕ: Int
    let first = string[string.startIndex]
    

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24. Collection
    let array = [10, 20, 30, 40, 50]
    let string = "abc͍͋͏͓͑"
    ఴࣈΞΫηε: Int
    ཁૉͷܕ: Int
    let first = string[string.startIndex]
    String.Index
    Character
    

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25. Collection
    let array = [10, 20, 30, 40, 50]
    let string = "abc͍͋͏͓͑"
    ఴࣈΞΫηε: Int
    ཁૉͷܕ: Int
    let startIdx = str.startIndex
    let index = str.index(startIdx, offsetBy: 5)
    let fifthChar = str[index]
    

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26. Collection
    let array = [10, 20, 30, 40, 50]
    let string = "abc͍͋͏͓͑"
    ఴࣈΞΫηε: Int
    ཁૉͷܕ: Int
    let startIdx = str.startIndex
    let index = str.index(startIdx, offsetBy: 5)
    let fifthChar = str[index]
    

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27. Collection
    let array = [10, 20, 30, 40, 50]
    let string = "abc͍͋͏͓͑"
    ఴࣈΞΫηε: Int
    ཁૉͷܕ: Int
    ఴࣈΞΫηε: String.Index
    ཁૉͷܕ: Character
    

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28. Collection
    var array = [ , 20, 30, 40, 50]
    var string = “ bc͍͋͏͓͑”
    ఴࣈΞΫηε: Int
    ཁૉͷܕ: Int
    ఴࣈΞΫηε: String.Index
    ཁૉͷܕ: Character
    10 Λ 100 ʹม͑Δ
    a Λ X ʹม͑Δ
    a
    10
    

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29. Collection
    X
    100
    var array = [ , 20, 30, 40, 50]
    var string = “ bc͍͋͏͓͑”
    ఴࣈΞΫηε: Int
    ཁૉͷܕ: Int
    ఴࣈΞΫηε: String.Index
    ཁૉͷܕ: Character
    

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30. Collection
    var array = [100, 20, 30, 40, 50]
    var string = "Xbc͍͋͏͓͑"
    ఴࣈΞΫηε: Int
    ཁૉͷܕ: Int
    ఴࣈΞΫηε: String.Index
    ཁૉͷܕ: Character
    array[0] = 100
    

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31. Collection
    var array = [100, 20, 30, 40, 50]
    var string = "Xbc͍͋͏͓͑"
    ఴࣈΞΫηε: Int
    ཁૉͷܕ: Int
    ఴࣈΞΫηε: String.Index
    ཁૉͷܕ: Character
    array[0] = 100
    "
    

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32. Collection
    var array = [100, 20, 30, 40, 50]
    var string = "Xbc͍͋͏͓͑"
    ఴࣈΞΫηε: Int
    ཁૉͷܕ: Int
    ఴࣈΞΫηε: String.Index
    ཁૉͷܕ: Character
    

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33. Collection
    var array = [100, 20, 30, 40, 50]
    var string = "Xbc͍͋͏͓͑"
    ఴࣈΞΫηε: Int
    ཁૉͷܕ: Int
    ఴࣈΞΫηε: String.Index
    ཁૉͷܕ: Character
    string[string.startIndex] = "X"
    

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34. Collection
    var array = [100, 20, 30, 40, 50]
    var string = "Xbc͍͋͏͓͑"
    ఴࣈΞΫηε: Int
    ཁૉͷܕ: Int
    ఴࣈΞΫηε: String.Index
    ཁૉͷܕ: Character
    string[string.startIndex] = "X"
    #
    

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35. Collection
    let array = [10, 20, 30, 40, 50]
    let string = "abc͍͋͏͓͑"
    ఴࣈΞΫηε: Int
    ཁૉͷܕ: Int
    ఴࣈʹΑΔมߋ: OK
    ఴࣈΞΫηε: String.Index
    ཁૉͷܕ: Character
    ఴࣈʹΑΔมߋ: NG
    

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36. Collection
    let array = [10, 20, 30, 40, 50]
    let string = "abc͍͋͏͓͑"
    ఴࣈΞΫηε: Int
    ཁૉͷܕ: Int
    ఴࣈʹΑΔมߋ: OK
    ఴࣈΞΫηε: String.Index
    ཁૉͷܕ: Character
    ఴࣈʹΑΔมߋ: NG
    

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37. Collection
    let array = [10, 20, 30, 40, 50]
    let string = "abc͍͋͏͓͑"
    ఴࣈΞΫηε: Int
    ཁૉͷܕ: Int
    ఴࣈʹΑΔมߋ: OK
    ఴࣈΞΫηε: String.Index
    ཁૉͷܕ: Character
    ఴࣈʹΑΔมߋ: NG
    

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38. Collection
    let array = [10, 20, 30, 40, 50]
    let string = "abc͍͋͏͓͑"
    ఴࣈΞΫηε: Int
    ཁૉͷܕ: Int
    ఴࣈʹΑΔมߋ: OK
    ఴࣈΞΫηε: String.Index
    ཁૉͷܕ: Character
    ఴࣈʹΑΔมߋ: NG
    count͸5
    count͸8
    

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39. Collection
    let array = [10, 20, 30, 40, 50]
    let string = "abc͍͋͏͓͑"
    ఴࣈΞΫηε: Int
    ཁૉͷܕ: Int
    ఴࣈʹΑΔมߋ: OK
    ఴࣈΞΫηε: String.Index
    ཁૉͷܕ: Character
    ఴࣈʹΑΔมߋ: NG
    

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40. ಉ͡Collectionͱ͍ͬͯ΋ѻ͍ํ
    ͕গ͠ҧ͏
    - Stringͷํ͕ѻ͍ʹ͍͘
    

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41. ΞδΣϯμ
    - SwiftͷStringʹ͍ͭͯ
    
    -Unicodeʹ͍ͭͯ
    - Stringͱཁૉͷஔ͖׵͑ʹ͍ͭͯ
    

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42. ʮͺʯͱ͍͏จࣈΛ

    UnicodeͰද͢
    ྫ
    

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43. ͺ ͺ
    let pa1 = “…”
    let pa2 = “…”
    print(pa1, pa2) // ͺ ͺ
    

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44. ͺ ͺ
    let pa1 = “…”
    let pa2 = “…”
    print(pa1, pa2) // ͺ ͺ
    

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45. ͺ ͺ
    จࣈ ͺ ͺ
    Unicode

    Scalar
    ͺ
    
    U+3071
    ͸
    
    U+306F
    㿇
    
    
    U+309A
    

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46. จࣈ ͺ ͺ
    Unicode

    Scalar
    ͺ
    
    U+3071
    ͸
    
    U+306F
    㿇
    
    
    U+309A
    

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47. จࣈ ͺ ͺ
    Unicode

    Scalar
    ͺ
    
    U+3071
    ͸
    
    U+306F
    㿇
    
    
    U+309A
    ʮͺʯΛද͢εΧϥ஋(͋Δछͷූ߸)୯ମͰʮͺʯΛද͢
    

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48. จࣈ ͺ ͺ
    Unicode

    Scalar
    ͺ
    
    U+3071
    ͸
    
    U+306F
    㿇
    
    
    U+309A
    

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49. จࣈ ͺ ͺ
    Unicode

    Scalar
    ͺ
    
    U+3071
    ͸
    
    U+306F
    㿇
    
    
    U+309A
    ʮ͸ʯͱʮ㿇
    ʯΛ૊Έ߹ΘͤͯʮͺʯΛද͢ɻ
    

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50. จࣈ ͺ ͺ
    Unicode

    Scalar
    ͺ
    
    U+3071
    ͸
    
    U+306F
    㿇
    
    
    U+309A
    

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51. จࣈ ͺ ͺ
    Unicode

    Scalar
    ͺ
    
    U+3071
    ͸
    
    U+306F
    㿇
    
    
    U+309A
    

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52. จࣈ ͺ ͺ
    Unicode

    Scalar
    ͺ
    
    U+3071
    ͸
    
    U+306F
    㿇
    
    
    U+309A
    

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53. จࣈ ͺ ͺ
    Unicode

    Scalar
    ͺ
    
    U+3071
    ͸
    
    U+306F
    㿇
    
    
    U+309A
    

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54. จࣈ ͺ ͺ
    Unicode

    Scalar
    ͺ
    
    U+3071
    ͸
    
    U+306F
    㿇
    
    
    U+309A
    

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55. จࣈ ͺ ͺ
    Unicode

    Scalar
    ͺ
    
    U+3071
    ͸
    
    U+306F
    㿇
    
    
    U+309A
    

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56. จࣈ ͺ ͺ
    Unicode

    Scalar
    ͺ
    
    U+3071
    ͸
    
    U+306F
    㿇
    
    
    U+309A
    

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57. จࣈ ͺ ͺ
    Unicode

    Scalar
    ͺ
    
    U+3071
    ͸
    
    U+306F
    㿇
    
    
    U+309A
    

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58. จࣈ ͺ ͺ
    Unicode

    Scalar
    ͺ
    
    U+3071
    ͸
    
    U+306F
    㿇
    
    
    U+309A
    

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59. จࣈ ͺ ͺ
    Unicode

    Scalar
    ͺ
    
    U+3071
    ͸
    
    U+306F
    㿇
    
    
    U+309A
    

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60. จࣈ ͺ ͺ
    Unicode

    Scalar
    ͺ
    
    U+3071
    ͸
    
    U+306F
    㿇
    
    
    U+309A
    

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61. View Slide

62. View Slide

63. View Slide

64. View Slide

65. จࣈ
    $ &
    Unicode

    Scalar
    U+1F469 U+200D U+1F692 U+1F3E3 U+1F1EF U+1F1F5
    

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66. จࣈ
    $ &
    Unicode

    Scalar
    U+1F469 U+200D U+1F692 U+1F3E3 U+1F1EF U+1F1F5
    
    

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67. ֦ுॻهૉΫϥελ
    

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68. ֦ுॻهૉΫϥελ
    • ӳޠͰ͸ Extended Grapheme Cluster
    

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69. https://developer.apple.com/documentation/swift/character
    

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70. https://developer.apple.com/documentation/swift/character
    

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71. https://developer.apple.com/documentation/swift/character
    

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72. https://developer.apple.com/documentation/swift/character
    

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73. ֦ுॻهૉΫϥελ
    • ӳޠͰ͸ Extended Grapheme Cluster
    
    • SwiftͷCharacterܕʹ֘౰
    

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74. ֦ுॻهૉΫϥελ
    • ӳޠͰ͸ Extended Grapheme Cluster
    
    • SwiftͷCharacterܕʹ֘౰
    
    • Ϣʔβʔʹͱͬͯͷʮ1จࣈʯ
    

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75. "\r\n"͸1จࣈ
    

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76. https://unicode.org/reports/tr29/#Grapheme_Cluster_Boundaries
    

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77. งғؾΛײͯ͡ΈΔ
    

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78. งғؾΛײͯ͡ΈΔ
    "ͺa\r\n&"
    

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79. U+306F U+309A U+0A U+1F146 U+200D U+1F692
    U+61 U+0D
    จࣈ ͺ a \r \n &
    Unicode

    Scalar
    U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
    

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80. U+306F U+309A U+0A U+1F146 U+200D U+1F692
    U+61 U+0D
    จࣈ ͺ a \r \n &
    Unicode

    Scalar
    U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
    1 2 3 4
    

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81. U+306F
    U+309A U+0A U+1F146 U+200D U+1F692
    U+61 U+0D
    จࣈ ͺ a \r \n &
    Unicode

    Scalar
    U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
    

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82. U+309A U+0A U+1F146 U+200D U+1F692
    U+61 U+0D
    จࣈ ͺ a \r \n &
    Unicode

    Scalar
    U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
    U+306F
    

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83. U+309A U+0A U+1F146 U+200D U+1F692
    U+61 U+0D
    จࣈ ͺ a \r \n &
    Unicode

    Scalar
    U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
    U+306F: ͻΒ͕ͳͷʮ͸ʯ
    

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84. U+309A
    U+0A U+1F146 U+200D U+1F692
    U+61 U+0D
    จࣈ ͺ a \r \n &
    Unicode

    Scalar
    U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
    U+306F: ͻΒ͕ͳͷʮ͸ʯ
    

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85. U+309A
    U+0A U+1F146 U+200D U+1F692
    U+61 U+0D
    จࣈ ͺ a \r \n &
    Unicode

    Scalar
    U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
    U+306F: ͻΒ͕ͳͷʮ͸ʯ
    

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86. U+309A: ʮ ʄʯ
    U+0A U+1F146 U+200D U+1F692
    U+61 U+0D
    จࣈ ͺ a \r \n &
    Unicode

    Scalar
    U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
    U+306F: ͻΒ͕ͳͷʮ͸ʯ
    

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87. U+309A: ʮ ʄʯ
    U+0A U+1F146 U+200D U+1F692
    U+61 U+0D
    จࣈ ͺ a \r \n &
    Unicode

    Scalar
    U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
    U+306F: ͻΒ͕ͳͷʮ͸ʯ
    Nonspacing Mark
    

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88. U+61
    U+309A: ʮ ʄʯ
    U+0A U+1F146 U+200D U+1F692
    U+0D
    จࣈ ͺ a \r \n &
    Unicode

    Scalar
    U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
    U+306F: ͻΒ͕ͳͷʮ͸ʯ
    

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89. U+61
    U+309A: ʮ ʄʯ
    U+0A U+1F146 U+200D U+1F692
    U+0D
    จࣈ ͺ a \r \n &
    Unicode

    Scalar
    U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
    U+306F: ͻΒ͕ͳͷʮ͸ʯ
    

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90. U+61: ʮaʯ
    U+309A: ʮ ʄʯ
    U+0A U+1F146 U+200D U+1F692
    U+0D
    จࣈ ͺ a \r \n &
    Unicode

    Scalar
    U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
    U+306F: ͻΒ͕ͳͷʮ͸ʯ
    

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91. U+61: ʮaʯ
    U+309A: ʮ ʄʯ
    U+0A U+1F146 U+200D U+1F692
    U+0D
    จࣈ ͺ a \r \n &
    Unicode

    Scalar
    U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
    U+306F: ͻΒ͕ͳͷʮ͸ʯ
    ͺ
    

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92. U+61: ʮaʯ
    U+0A U+1F146 U+200D U+1F692
    U+0D
    จࣈ ͺ a \r \n &
    Unicode

    Scalar
    U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
    

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93. U+61: ʮaʯ
    U+0A U+1F146 U+200D U+1F692
    U+0D
    จࣈ ͺ a \r \n &
    Unicode

    Scalar
    U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
    

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94. U+61: ʮaʯ
    U+0A U+1F146 U+200D U+1F692
    U+0D
    จࣈ ͺ a \r \n &
    Unicode

    Scalar
    U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
    

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95. U+61: ʮaʯ
    U+0A U+1F146 U+200D U+1F692
    U+0D: Carriage Return
    จࣈ ͺ a \r \n &
    Unicode

    Scalar
    U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
    

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96. U+61: ʮaʯ
    U+0A U+1F146 U+200D U+1F692
    U+0D: Carriage Return
    จࣈ ͺ a \r \n &
    Unicode

    Scalar
    U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
    a
    

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97. U+0A U+1F146 U+200D U+1F692
    U+0D: Carriage Return
    จࣈ ͺ a \r \n &
    Unicode

    Scalar
    U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
    

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98. U+1F146 U+200D U+1F692
    U+0D: Carriage Return
    U+0A
    จࣈ ͺ a \r \n &
    Unicode

    Scalar
    U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
    

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99. U+1F146 U+200D U+1F692
    U+0D: Carriage Return
    U+0A
    จࣈ ͺ a \r \n &
    Unicode

    Scalar
    U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
    

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100. U+1F146 U+200D U+1F692
     U+0D: Carriage Return
     U+0A: Line Feed
     จࣈ ͺ a \r \n &
     Unicode

     Scalar
     U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
     

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101. U+1F146 U+200D U+1F692
     U+0D: Carriage Return
     U+0A: Line Feed
     จࣈ ͺ a \r \n &
     Unicode

     Scalar
     U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
     \r\n ͷ૊Έ߹Θͤ͸
     ಛผѻ͍
     

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102. U+1F146 U+200D U+1F692
     จࣈ ͺ a \r \n &
     Unicode

     Scalar
     U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
     

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103. U+200D U+1F692
     U+1F1EF
     จࣈ ͺ a \r \n &
     Unicode

     Scalar
     U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
     

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104. U+200D U+1F692
     U+1F1EF
     จࣈ ͺ a \r \n &
     Unicode

     Scalar
     U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
     

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105. U+200D U+1F692
     U+1F1EF:
     จࣈ ͺ a \r \n &
     Unicode

     Scalar
     U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
     J
     

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106. U+200D U+1F692
     U+1F1EF:
     จࣈ ͺ a \r \n &
     Unicode

     Scalar
     U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
     ࠃίʔυͷʮJʯ
     J
     

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107. U+200D
     U+1F1EF:
     U+1F1F5
     จࣈ ͺ a \r \n &
     Unicode

     Scalar
     U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
     J
     

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108. U+200D
     U+1F1EF:
     U+1F1F5
     จࣈ ͺ a \r \n &
     Unicode

     Scalar
     U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
     J
     

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109. U+200D
     U+1F1EF:
     U+1F1F5:
     จࣈ ͺ a \r \n &
     Unicode

     Scalar
     U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
     J
     P
     

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110. U+200D
     U+1F1EF:
     U+1F1F5:
     จࣈ ͺ a \r \n &
     Unicode

     Scalar
     U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
     J
     P
     ࠃίʔυʮJʯ+ʮPʯ
     Ͱ೔ຊ
     

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111. U+200D
     จࣈ ͺ a \r \n &
     Unicode

     Scalar
     U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
     

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112. U+200D
     จࣈ ͺ a \r \n &
     Unicode

     Scalar
     U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
     1 2 3 4
     

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113. U+200D
     จࣈ ͺ a \r \n &
     Unicode

     Scalar
     U+306F U+309A U+61 U+0D U+0A U+1F1EF U+1F1F5
     1 2 3 4
     ΋͠\nͰ͸ͳͯ͘ʮbʯ
     ͩͬͨΒ
     

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114. U+200D
     จࣈ ͺ a \r b &
     Unicode

     Scalar
     U+306F U+309A U+61 U+0D U+62 U+1F1EF U+1F1F5
     1 2 3 4
     

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115. U+200D
     จࣈ ͺ a \r b &
     Unicode

     Scalar
     U+306F U+309A U+61 U+0D U+62 U+1F1EF U+1F1F5
     1 2 3 4
     \r ͱ b ͸݁߹͠ͳ͍
     

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116. U+200D
     จࣈ ͺ a \r b &
     Unicode

     Scalar
     U+306F U+309A U+61 U+0D U+62 U+1F1EF U+1F1F5
     1 2 3 4 5
     

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117. U+200D
     จࣈ ͺ a \r b &
     Unicode

     Scalar
     U+306F U+309A U+61 U+0D U+62 U+1F1EF U+1F1F5
     1 2 3 4 5
     4จࣈ໨ͩͬͨ΋ͷ͕
     5จࣈ໨ʹ
     

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118. U+200D
     จࣈ ͺ a \r b &
     Unicode

     Scalar
     U+306F U+309A U+61 U+0D U+62 U+1F1EF U+1F1F5
     1 2 3 4 5
     N൪໨ͷจࣈΛ஌ΔͨΊʹ͸ɺ
     ͦͷલʹ͋ΔจࣈΛ஌Δඞཁ͕͋Δɻ
     

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119. U+200D
     จࣈ ͺ a \r b &
     Unicode

     Scalar
     U+306F U+309A U+61 U+0D U+62 U+1F1EF U+1F1F5
     1 2 3 4 5
     N൪໨ͷจࣈΛ஌ΔͨΊʹ͸ɺ
     ͦͷલʹ͋ΔจࣈΛ஌Δඞཁ͕͋Δɻ
     ‑
     N൪໨ͷจࣈΛऔಘ͢ΔͨΊͷܭࢉྔ͸O(N)
     

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120. U+200D
     จࣈ ͺ a \r b &
     Unicode

     Scalar
     U+306F U+309A U+61 U+0D U+62 U+1F1EF U+1F1F5
     1 2 3 4 5
     N൪໨ͷจࣈΛ஌ΔͨΊʹ͸ɺ
     ͦͷલʹ͋ΔจࣈΛ஌Δඞཁ͕͋Δɻ
     ‑
     N൪໨ͷจࣈΛऔಘ͢ΔͨΊͷܭࢉྔ͸ O(N)
     

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121. ܭࢉྔ
     ܭࢉʹ͔͔Δ࣌ؒ
     จࣈͷҐஔ
     

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122. ܭࢉྔ
     ܭࢉʹ͔͔Δ࣌ؒ
     จࣈͷҐஔ
     O(N)
     

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123. String͸Collectionʹ४ڌ
     • ఴࣈΞΫηεͷܭࢉྔ͸O(1)Ͱͳ͍ͱ͍͚ͳ͍
     

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124. ܭࢉྔ
     ܭࢉʹ͔͔Δ࣌ؒ
     จࣈͷҐஔ
     O(N)
     

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125. ܭࢉྔ
     ܭࢉʹ͔͔Δ࣌ؒ
     จࣈͷҐஔ
     O(N)
     Collectionϓϩτίϧͷ
     ཁ੥
     

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126. ܭࢉྔ
     ܭࢉʹ͔͔Δ࣌ؒ
     จࣈͷҐஔ
     IntͰఴࣈΞΫηεͨ͠ͱ͖ʹ͔
     ͔Δ࣌ؒ O(N)
     Collectionϓϩτίϧͷ
     ཁ੥ O(1)
     

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127. ܭࢉྔ
     ܭࢉʹ͔͔Δ࣌ؒ
     จࣈͷҐஔ
     IntͰఴࣈΞΫηεͨ͠ͱ͖ʹ͔
     ͔Δ࣌ؒ O(N)
     Collectionϓϩτίϧͷ
     ཁ੥ O(1)
     String͸IntͰ͸ఴࣈΞΫηε
     Ͱ͖ͳ͍
     

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128. StringͷఴࣈΞΫηεʹ͍ͭͯ
     

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129. String.Index
     StringͷఴࣈΞΫηεʹ͍ͭͯ
     

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130. String.Index
     StringͷఴࣈΞΫηεʹ͍ͭͯ
     ࢝఺͔ΒͷΦϑηοτ
     

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131. ΞδΣϯμ
     - SwiftͷStringʹ͍ͭͯ
     
     - Unicodeʹ͍ͭͯ
     
     -Stringͱཁૉͷஔ͖׵͑ʹ͍ͭͯ
     

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132. ཁૉͷஔ͖׵͕͑Ͱ͖ͳ͍
     

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133. Array
     String
     "
     #
     

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134. Array
     String
     "
     #
     ఴࣈΞΫηεͰsetͰ͖Δ
     ఴࣈΞΫηεͰsetͰ͖ͳ͍
     

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135. Array
     String
     "
     #
     ఴࣈΞΫηεͰsetͰ͖Δ
     ఴࣈΞΫηεͰsetͰ͖ͳ͍
     MutableCollectionʹ४ڌ͍ͯ͠Δ
     MutableCollectionʹ४ڌ͍ͯ͠ͳ͍
     

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136. Array
     String
     "
     #
     ఴࣈΞΫηεͰsetͰ͖Δ
     ఴࣈΞΫηεͰsetͰ͖ͳ͍
     MutableCollectionʹ४ڌ͍ͯ͠Δ
     MutableCollectionʹ४ڌ͍ͯ͠ͳ͍
     

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137. Sequence
     Collection
     MutableCollection
     

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138. Sequence
     Collection
     MutableCollection
     - ఴࣈΞΫηεʹΑΔgetΛ
     ఆٛ
     - ఴࣈΞΫηεʹΑΔsetΛ
     ఆٛ
     

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139. Sequence
     Collection
     MutableCollection
     - ఴࣈΞΫηεʹΑΔgetΛ
     ఆٛ
     - ఴࣈΞΫηεʹΑΔsetΛ
     ఆٛ
     ܭࢉྔ͸O(1)
     ͲͪΒ΋ܭࢉྔ͸O(1)
     

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140. Sequence
     Collection
     MutableCollection
     String
     Sequence
     Collection
     MutableCollection
     Array
     

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141. Sequence
     Collection
     MutableCollection
     String
     Sequence
     Collection
     MutableCollection
     Array
     ఴࣈΞΫηεʹΑΔset
     ͕O(1)Ͱ࣮ݱͰ͖ͳ͍͔Β
     

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142. จࣈ ͏ a b c
     Unicode

     Scalar
     U+3046 U+61 U+62 U+63
     var string = “͏abc"
     string[string.startIndex] = "X"
     

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143. จࣈ ͏ a b c
     Unicode

     Scalar
     U+3046 U+61 U+62 U+63
     var string = “͏abc"
     string[string.startIndex] = "X"
     

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144. จࣈ X a b c
     Unicode

     Scalar
     U+58 U+61 U+62 U+63
     var string = “͏abc"
     string[string.startIndex] = "X"
     

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145. จࣈ ͏ a b c
     Unicode

     Scalar
     U+3046 U+61 U+62 U+63
     จࣈ X a b c
     Unicode

     Scalar
     U+58 U+61 U+62 U+63
     

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146. จࣈ ͏ a b c
     Unicode

     Scalar
     U+3046 U+61 U+62 U+63
     UTF-8 E3 81 85 61 62 63
     จࣈ X a b c
     Unicode

     Scalar
     U+58 U+61 U+62 U+63
     UTF-8 58 61 62 63
     

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147. จࣈ ͏ a b c
     Unicode

     Scalar
     U+3046 U+61 U+62 U+63
     UTF-8 E3 81 85 61 62 63
     จࣈ X a b c
     Unicode

     Scalar
     U+58 U+61 U+62 U+63
     UTF-8 58 61 62 63
     

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148. จࣈ ͏ a b c
     Unicode

     Scalar
     U+3046 U+61 U+62 U+63
     UTF-8 E3 81 85 61 62 63
     όΠτ෯ 3 1 1 1
     จࣈ X a b c
     Unicode

     Scalar
     U+58 U+61 U+62 U+63
     UTF-8 58 61 62 63
     όΠυ෯ 1 1 1 1
     

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149. View Slide

150. 1όΠτ
     

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151. a b c
     ͏
     

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152. a b c
     ͏
     a b c
     X
     

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153. a b c
     ͏
     a b c
     X
     

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154. a c
     b
     ͏
     b c
     a
     X
     ೖΕସ͑ͨจࣈͷҎ߱ͷจࣈͷόΠτྻΛҠಈ͢Δඞཁ͕͋Δ
     ‑
     ఴࣈΞΫηεʹΑΔ set ͷܭࢉྔ͸O(N)
     

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155. ·ͱΊ
     - ҰͭͷCharacterͷ಺෦දݱ͕ͦΕͧΕҟͳΔͷͰɺ
     CharacterͷऔಘͱೖΕସ͑ͷܭࢉྔ͕O(1)ʹͳΒͳ͍
     - IntͰఴࣈΞΫηεͰ͖ͳ͍
     - MutableCollectionʹ४ڌ͠ͳ͍
     

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