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nseg92 kotlin Null Safety

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September 16, 2017

nseg92 kotlin Null Safety

Avatar for hATrayflood

hATrayflood

September 16, 2017
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  1. y y 2017/9/16 NSEG Vol.92 ( ・∀・)  | | ガッ と    )   | | Y /ノ    

    ⼈ / )  <  >__Λ ∩ _/し' // V`Д´)/ ←>>1 (_フ⼺          / by ABE Hiroki aka hATrayflood
  2. y y 2017/9/16 NSEG Vol.92 val hoge: String = null

    コンパイルエラー by ABE Hiroki aka hATrayflood
  3. y y 2017/9/16 NSEG Vol.92 fun setHoge(hoge: String) { this.hoge

    = hoge } by ABE Hiroki aka hATrayflood
  4. y y 2017/9/16 NSEG Vol.92 fun getFuga(): String? { return

    null } by ABE Hiroki aka hATrayflood
  5. y y 2017/9/16 NSEG Vol.92 fun setHoge(hoge: String) { this.hoge

    = hoge } fun getFuga(): String? { return "fuga" } val fuga = getFuga() setHoge(fuga) by ABE Hiroki aka hATrayflood
  6. y y 2017/9/16 NSEG Vol.92 val fuga = getFuga() if(fuga

    != null){ setHoge(fuga) } by ABE Hiroki aka hATrayflood
  7. y y 2017/9/16 NSEG Vol.92 val fuga = getFuga() setHoge(fuga

    ?: "fuga") by ABE Hiroki aka hATrayflood
  8. y y 2017/9/16 NSEG Vol.92 fun getHage(): Hage? { return

    Hage() } val hage = getHage() hage.setHoge("hoge") by ABE Hiroki aka hATrayflood
  9. y y 2017/9/16 NSEG Vol.92 val hage = getHage() as

    Hage hage.setHoge("hoge") by ABE Hiroki aka hATrayflood
  10. y y 2017/9/16 NSEG Vol.92 as でキャストすると 強引に ? を外せます

    中⾝はnullもあるので ぬるぽの危険あり by ABE Hiroki aka hATrayflood
  11. by ABE Hiroki aka hATrayflood y y 2017/9/16 NSEG Vol.92

    ・リンク集 twitter @hATrayflood http://twitter.com/hATrayflood Kotlin Programming Language http://kotlinlang.org/ KotlinがAndroid開発⾔語になる https://www.infoq.com/jp/news/2017/05/android-kotlin 【!ってなんだ】KotlinとJava、nullとPlatformType【NullableにNotNull】 - Qiita http://qiita.com/RyotaMurohoshi/items/5fcc10d04fecd7304556 JavaプログラマがKotlinでつまづきがちなところ - Qiita http://qiita.com/koher/items/d9411a00986f14683a3f Kotlin : as, !, ? 周りのチートシート - i++ http://increment.hatenablog.com/entry/2015/10/31/090743 by ABE Hiroki aka hATrayflood
  12. y y