Mobile Programming Initializer Beta

モバイルプログラミングの授業で使うスライドです

Transcript

1. ΠχγϟϥΠβ
   MOBILE PROGRAMMING 18TH NOV
   

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2. 1. Πχγϟϥ
   Πβͷجຊ
   

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3. ςΩετ
   ΠχγϟϥΠβʁ
   ▸ JavaͰݴ͏ॴͷίϯετϥΫλ
   ▸ ΫϥεΛॳظԽ͠ѻ͑ΔΑ͏ʹ४උΛߦ͏৔ॴ
   ▸ ॳظԽ͸ओʹϓϩύςΟʹॳظ஋Ληοτͨ͠ΓඞཁʹԠ͡
   ͯϝιου΋ݺͿ
   ▸ SwiftͰ͸ඞͣ init() { … } ͱ͍͏໊લʹͳΔ
   ▸ ΠχγϟϥΠβͰ͸શͯͷϓϩύςΟΛॳظԽ͢Δ·Ͱϝιο
   υ΍ଞͷϓϩύςΟʹΞΫηεͰ͖ͳ͍
   

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4. ςΩετ
   ࣮ࡍͷίʔυ
   class Pokemon {
   let name: String
   var ability: Ability
   var level: Int
   fileprivate(set) var health: Int = 1
   fileprivate var healthFactor: Int { return 1 }
   fileprivate var baseHealth: Int { return 10 }
   init(name: String, level: Int, ability: Ability) {
   self.name = name
   self.ability = ability
   self.level = level
   self.health = self.baseHealth + level * self.healthFactor
   }
   }
   ·ͣ͸஋͕ೖͬͯͳ͍ϓϩύςΟΛॳظԽ
   શͯͷϓϩύςΟʹ஋͕ೖΔͱbaseHealth ΍ healthFactorʹ
   ΞΫηεͰ͖Δ
   

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5. ςΩετ
   ͳͥશͯͷϓϩύςΟΛೖΕͳ͍ͱ͍͚ͳ͍͔
   ▸ Ҏલ࢖ΘΕ͍ͯͨObjective-CͳͲͷݴޠͰ͸ॳظԽ͕͞Ε͍ͯͳ͍৔߹͸nilͳͲ
   ΛೖΕͯڧҾʹॳظԽΛ͍ͯͨ͠
   ▸ ͜ͷڍಈΛڐͯ͠͠·͏ͱ༧ظͤ͵Τϥʔ͕ى͜Δ͜ͱ͕͋Δ(Null Pointer
   Exceptionͱ͔)
   ▸ SwiftͰ͸ͦΜͳ͜ͱ͕ى͜Βͳ͍Α͏ʹίϯύΠϧ࣌ʹม਺΍ఆ਺ʹ஋͕͖ͪΜͱ
   ೖ͍ͬͯΔ͔νΣοΫ͢ΔΑ͏ʹͳ͍ͬͯΔ
   ▸ ͜ΕʹΑΓ஋ΛೖΕͯͨͱࢥ͚ͬͯͨͲೖΕͯͳ͔ͬͨʂ
   ▸ ͱ͍ͬͨώϡʔϚϯΤϥʔΛճආ͢Δ͜ͱ͕Ͱ͖Δ
   ▸ Swiftͬͯૉఢɾɾɾૉఢ͡Όͳ͍ʁ
   

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6. 2. ৭ʑͳΠχ
   γϟϥΠβ
   

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7. ςΩετ
   ৭ʑͳΠχγϟϥΠβ
   ▸ Failable Initializer
   ▸ Default Initializer
   ▸ Memberwise Initializer
   ▸ Designated Initializer
   ▸ Convenience Initializer
   ▸ Required Initializer
   

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8. ςΩετ
   ৭ʑͳΠχγϟϥΠβ
   ▸ Failable Initializer: ࣦഊՄೳΠχγϟϥΠβ
   ▸ Default Initializer: نఆΠχγϟϥΠβ
   ▸ Memberwise Initializer: શ߲໨ΠχγϟϥΠβ
   ▸ Designated Initializer: ࢦఆΠχγϟϥΠβ
   ▸ Convenience Initializer: ؆қΠχγϟϥΠβ
   ▸ Required Initializer: ඞਢΠχγϟϥΠβ
   

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9. ΦΦεΪΟʂ
   

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10. 2-1. ࢦఆΠχγϟ
    ϥΠβ
    

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11. ςΩετ
    ࢦఆΠχγϟϥΠβ?
    ▸ ҰൠతͳΠχγϟϥΠβ
    ▸ ࢦఆΠχγϟϥΠβͰ͸ϓϩύςΟʹ͢΂ͯ஋Ληοτ͢Δ
    ඞཁ͕͋Δ
    ▸ ॳظ஋͕ηοτ͞Ε͍ͯͳ͍ϓϩύςΟ͕ఆٛͯ͋͠Δ৔߹
    ͸ඞͣ͜ͷλΠϓͷΠχγϟϥΠβΛఆٛ͠ͳͯ͘͸͍͚ͳ
    ͍
    

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12. ςΩετ
    ࣮ࡍͷίʔυ
    class Pokemon {
    let name: String
    var ability: Ability
    var level: Int
    fileprivate(set) var health: Int = 1
    fileprivate var healthFactor: Int { return 1 }
    fileprivate var baseHealth: Int { return 10 }
    init(name: String, level: Int, ability: Ability) {
    self.name = name
    self.ability = ability
    ɹɹɹɹ self.level = level
    self.health = self.baseHealth + level * self.healthFactor
    }
    }
    ࢦఆΠχγϟϥΠβ
    

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13. 2-2. نఆΠχ
    γϟϥΠβ
    

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14. ςΩετ
    نఆΠχγϟϥΠβ(DEFAULT INITIALIZER)?
    ▸ ීஈ͋·Γҙࣝ͠ͳ͍ΠχγϟϥΠβ
    ▸ Ϋϥεʹఆٛ͞Ε͍ͯΔϓϩύςΟʹॳظ஋͕શͯೖ͍ͬͯ
    Δ৔߹ʹ҉໧తʹఆٛ͞ΕΔ
    ▸
    

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15. ςΩετ
    ࣮ࡍͷίʔυ
    class Pokemon {
    let name: String = "Pikachu"
    var level: Int = 100
    fileprivate(set) var health: Int = 1
    fileprivate var healthFactor: Int { return 1 }
    fileprivate var baseHealth: Int { return 10 }
    // ҉໧తʹΠχγϟϥΠβ͕ఆٛ͞ΕΔ
    }
    let pikachu = Pokemon()
    

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16. 2-3. ࣦഊՄೳΠ
    χγϟϥΠβ
    

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17. ςΩετ
    ࣦഊՄೳΠχγϟϥΠβ(FAILABLE INITIALIZER)?
    ▸ ໊લͷ௨Γࣦഊ͢Δ͜ͱ͕Ͱ͖ΔΠχγϟϥΠβ
    ▸ ॳظԽ࣌ʹࣦഊ͢Δ͜ͱ͕͋ΔΫϥεʹ͸͜ΕΛఆٛ͢Δ
    ▸ ࣦഊ͢Δͱ͸ྫ͑͹จࣈྻ͔Β਺஋΁ͷม׵ͷࣦഊͰ͋Δ
    ▸ ΫϥεΛ͏·͘ॳظԽͰ͖ͳ͍͜ͱ͕͋ΔͷͰ໭Γ஋͸
    OptionalܕʹͳΔ
    ▸ จ๏͸ init?() { … }
    

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18. ςΩετ
    ࣮ࡍͷίʔυ
    class WebPage {
    let title: String
    let url: URL
    init?(title: String, urlString: String) {
    guard let url = URL(string: urlString) else { return nil }
    self.title = title
    self.url = url
    }
    }
    let google: WebPage? = WebPage(title: "google", urlString:
    "https://www.google.com")
    Failable Initializer
    ࣦഊ͢Δ͜ͱ͕͋ΔͷͰ OptionalܕʹͳΔ
    

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19. 2-4. ඞਢΠχ
    γϟϥΠβ
    

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20. ςΩετ
    ඞਢΠχγϟϥΠβ(REQUIRED INITIALIZER)?
    ▸ ໊લͷ௨Γඞ࣮ͣ૷͠ͳͯ͘͸͍͚ͳ͍ΠχγϟϥΠβ
    ▸ จ๏͸ required init() { … }
    ▸ UIViewͳͲը໘ʹؔΘΔ෦෼Ͱ͔͋͠·Γ࢖ΘΕͳ͍
    

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21. ςΩετ
    ࣮ࡍͷίʔυ
    class Pokemon {
    let name: String
    var ability: Ability
    var level: Int
    fileprivate(set) var health: Int = 1
    fileprivate var healthFactor: Int { return 1 }
    fileprivate var baseHealth: Int { return 10 }
    required init(name: String, level: Int, ability: Ability) {
    self.name = name
    self.ability = ability
    ɹɹɹɹ self.level = level
    self.health = self.baseHealth + level * self.healthFactor
    }
    }
    ඞਢΠχγϟϥΠβ
    

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22. ςΩετ
    ࣮ࡍͷίʔυ
    // ͬͪ͜͸Τϥʔ
    class Pikachu: Pokemon {
    init(level: Int) {
    let ability = Ability(name: "ͰΜ͖γϣοΫ", damage: 20)
    super.init(name: "ϐΧνϡ΢", level: level, ability: ability)
    }
    }
    

    // ͜Ε͸OK
    class Pikachu: Pokemon {
    required override init(name: String, level: Int, ability: Ability) {
    super.init(name: name, level: level, ability: ability)
    }
    }
    

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23. 2-5. ؆қΠχ
    γϟϥΠβ
    

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24. ςΩετ
    ؆қΠχγϟϥΠβ (CONVENIENCE INITIALIZER)?
    ▸ ؆қతͳΠχγϟϥΠβ
    ▸ جຊతʹࢦఆΠχγϟϥΠβͱηοτͰఆٛ͞ΕΔαϒͷΠ
    χγϟϥΠβ
    ▸ ࢦఆΠχγϟϥΠβͰ͸ϓϩύςΟʹ͢΂ͯ஋Ληοτ͢Δ
    ඞཁ͕͋Δ
    ▸ ॳظ஋͕ηοτ͞Ε͍ͯͳ͍ϓϩύςΟ͕ఆٛͯ͋͠Δ৔߹
    ͸ඞͣ͜ͷλΠϓͷΠχγϟϥΠβΛఆٛ͠ͳͯ͘͸͍͚ͳ
    ͍
    

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25. ςΩετ
    ࣮ࡍͷίʔυ
    class Pokemon {
    let name: String
    var ability: Ability
    var level: Int = 0
    fileprivate(set) var health: Int = 1
    init(name: String, level: Int, ability: Ability) {
    self.name = name
    self.level = level
    self.ability = ability
    self.health = level * 5
    }
    convenience init(level: Int) {
    let ability = Ability(name: "ѱ͕͖͋", damage: 40)
    self.init(name: "͚ͭ͹Μ", level: level, ability: ability)
    }
    }
    ؆қΠχγϟϥΠβ
    

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26. ςΩετ
    ࣮ࡍͷίʔυ
    class Pokemon {
    let name: String
    var ability: Ability
    var level: Int = 0
    fileprivate(set) var health: Int = 1
    init(name: String, level: Int, ability: Ability) {
    self.name = name
    self.level = level
    self.ability = ability
    self.health = level * 5
    }
    convenience init(level: Int) {
    let ability = Ability(name: "ѱ͕͖͋", damage: 40)
    self.init(name: "͚ͭ͹Μ", level: level, ability: ability)
    }
    }
    ؆қΠχγϟϥΠβ
    جຊతʹࢦఆΠχγϟϥΠβͱηοτͰఆٛ͞ΕΔ
    

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27. ςΩετ
    ࣮ࡍͷίʔυ
    class Pokemon {
    let name: String
    var ability: Ability
    var level: Int = 0
    fileprivate(set) var health: Int = 1
    init(name: String, level: Int, ability: Ability) {
    self.name = name
    self.level = level
    self.ability = ability
    self.health = level * 5
    }
    convenience init(level: Int) {
    let ability = Ability(name: "ѱ͕͖͋", damage: 40)
    self.init(name: "͚ͭ͹Μ", level: level, ability: ability)
    }
    }
    ؆қΠχγϟϥΠβ
    جຊతʹࢦఆΠχγϟϥΠβͱηοτͰఆٛ͞ΕΔ
    ඞͣଞͷࢦఆΠχγϟϥΠβ͔
    ਌ΫϥεͷΠχγϟϥΠβΛݺͼग़͢
    

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28. 2-6. શ߲໨Π
    χγϟϥΠβ
    

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29. ςΩετ
    શ߲໨ΠχγϟϥΠβ (MEMBERWISE INITIALIZER)?
    ▸ গʑಛघͳΠχγϟϥΠβ
    ▸ classʹ͸ଘࡏͤͣ struct ʹͷΈੜ੒͞ΕΔΠχγϟϥΠβ
    ▸ structʹΠχγϟϥΠβΛҰͭ΋ఆٛ͠ͳ͍৔߹ɺఆٛ͞Ε
    ͍ͯΔϓϩύςΟશͯΛҾ਺ʹؚΜͩΠχγϟϥΠβ͕҉໧
    తʹఆٛ͞Ε͍ͯΔ
    ▸ σʔλΛϞσϦϯά͚ͨͩ͠ͷstructͳͲΛఆٛͨ͠ࡍʹ͢
    ͘͝ศར
    

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30. ςΩετ
    ࣮ࡍͷίʔυ
    struct Ability {
    let name: String
    let type: String
    let damage: Int
    let hitRate: Int
    // ҉໧తʹҎԼͷΑ͏ͳΠχγϟϥΠβ͕ఆٛ͞ΕΔ
    /*
    init(name: String, type: String, damage: Int, hitRate: Int) {
    self.name = name
    self.type = type
    self.damage = damage
    self.hitRate = hitRate
    }
    */
    }
    let ability = Ability(
    name: "ίϝοτύϯν",
    type: "͸͕Ͷ",
    damage: 90,
    hitRate: 90
    )
    શͯͷϓϩύςΟΛؚΜͩΠχγϟϥΠβ͕࢖͑Δ
    

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31. ͱ͜ΖͰSTRUCTͬ
    ͯʁ
    

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