Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Speaker Deck
PRO
Sign in
Sign up for free
Trap Questions in Java and Obj-C
417.72KI
December 03, 2019
Programming
1
170
Trap Questions in Java and Obj-C
417.72KI
December 03, 2019
Tweet
Share
More Decks by 417.72KI
See All by 417.72KI
CLIツールにSwift Concurrencyを適用させようとしている話
417_72ki
3
160
CI with Danger-Swift
417_72ki
1
90
Graduation from Playground beginner
417_72ki
3
760
ダックタイピングとidでUserDefaultsをモック化する
417_72ki
2
1.9k
Mockable UserDefaults with Duck typing
417_72ki
0
500
Git Hooks
417_72ki
1
210
Management of Environment Variables with YAMLs Ver.2
417_72ki
2
770
Management of Environment Variables with YAMLs
417_72ki
1
500
iOS And GitLab-CI
417_72ki
1
2.5k
Other Decks in Programming
See All in Programming
プロダクトのタイプ別 GraphQL クライアントの選び方
shozawa
0
4.6k
Jetpack Composeでの画面遷移
iwata_n
0
170
設計の学び方:自分流のススメ
masuda220
PRO
8
6k
Swift Regex
usamik26
0
180
【Scrum Fest Osaka 2022】スクラムチームに放り込まれた若手エンジニアの皆さん、どのように技術のキャッチアップをしていくかイメージはついていますか?
miiiki
0
110
Beyond Micro Frontends: Frontend Moduliths for the Enterprise @enterjs2022
manfredsteyer
PRO
0
180
マルチプロダクト×非構造化データ×機械学習を支えるデータ信頼性
akino
0
140
短納期でローンチした新サービスをJavaで開発した話/launched new service using Java
eichisanden
6
1.9k
heyにおけるCI/CDの現状と課題
fufuhu
2
560
Meet Swift Regex
usamik26
0
350
Independently together: better developer experience & App performance
bcinarli
0
180
CSE360 Tutorial 07
javiergs
PRO
0
100
Featured
See All Featured
How STYLIGHT went responsive
nonsquared
85
3.9k
Gamification - CAS2011
davidbonilla
75
3.9k
VelocityConf: Rendering Performance Case Studies
addyosmani
316
22k
Why You Should Never Use an ORM
jnunemaker
PRO
47
7.6k
JazzCon 2018 Closing Keynote - Leadership for the Reluctant Leader
reverentgeek
172
8.4k
A Philosophy of Restraint
colly
192
15k
ReactJS: Keep Simple. Everything can be a component!
pedronauck
655
120k
Optimizing for Happiness
mojombo
365
63k
Visualizing Your Data: Incorporating Mongo into Loggly Infrastructure
mongodb
29
4.3k
GraphQLとの向き合い方2022年版
quramy
16
8.3k
Navigating Team Friction
lara
175
11k
Fight the Zombie Pattern Library - RWD Summit 2016
marcelosomers
226
15k
Transcript
4XJGU,PUMJOѪձ 7PM !(.0ϖύϘ
4XJGUͱ,PUMJO
4XJGUͱ,PUMJO
+BWBͱ0CKFDUJWF$ ͷΛ͠·͢
ͳΜͰࠓ͞Β+BWB0CK$
ͳΜͰࠓ͞Β+BWB0CK$ w ࠓͷ࣌ΞϓϦ4XJGU,PUMJOͰॻ͘ͷ͕ͨΓલ w ࠓͲ͖+BWB0CK$ͳΜͯ৮ΒΜΖ
Ռͨͯ͠ຊʹͦ͏ͩΖ͏͔ʁ
Ռͨͯ͠ຊʹͦ͏ͩΖ͏͔ʁ w 044ϥΠϒϥϦϦϦʔε͞Εͨ࣌ϥΠϒϥϦͷಛ ੑ্+BWB0CK$Ͱॻ͔Ε͍ͯΔͷ·ͩ·ͩଟ͍ w ࣮Λ֬ೝͨ͠Γ13Λग़ͨ͠Γ͢ΔͳΒͬͺΓͦͷล ͷࣝඞཁ
ͱ͍͏͜ͱͰ
ҙ֎ͱҾ͔͔ͬΔʂʁ ݴޠ༷ΫΠζ +BWB0CKFDUJWF$ฤ
w 5BLVIJSP.VUBBLB໊Նر ,* w 4& 8FC J04 "OESPJE ৽ਓݚमߨࢣFUD
J04 डୗ։ൃ J04 ࣗࣾ։ൃ ࠓίί w 5XJUUFS 2JJUB@LJ (JU)VC,* w 4XJGUѪձࢀՃप ͏ΜΧϨʔ ͓લ୭Α
#VJME$POpHTXJGU ελʔ͍ͩ͘͞
ݴޠ༷ΫΠζ w +BWB w 0CKFDUJWF$
+BWBฤ
ୈ
࣍ͷίʔυͷಈ͖Ͳ͏ͳΔʁ
࣍ͷίʔυͷಈ͖Ͳ͏ͳΔʁ public class Sample { public static void main(String... args)
{ while (false) { System.out.println("hoge"); } } }
࣍ͷίʔυͷಈ͖Ͳ͏ͳΔʁ public class Sample { public static void main(String... args)
{ while (false) { System.out.println("hoge"); } } } lIPHFz͕ճ͚ͩग़ྗ͞ΕΔ Կى͖ͳ͍ ίϯύΠϧΤϥʔ ࣮ߦ࣌Τϥʔ
࣍ͷίʔυͷಈ͖Ͳ͏ͳΔʁ public class Sample { public static void main(String... args)
{ while (false) { System.out.println("hoge"); } } } lIPHFz͕ճ͚ͩग़ྗ͞ΕΔ Կى͖ͳ͍ ίϯύΠϧΤϥʔ ࣮ߦ࣌Τϥʔ
ղઆ public class Sample { public static void main(String... args)
{ while (false) { System.out.println("hoge"); } } } 6OSFBDIBCMFDPEF
ୈ
ୈΛ౿·͑ͯ public class Sample { public static void main(String... args)
{ while (false) { System.out.println("hoge"); } } }
࣍ͷίʔυͷಈ͖Ͳ͏ͳΔʁ public class Sample { public static void main(String... args)
{ do { System.out.println("hoge"); } while (false); } }
࣍ͷίʔυͷಈ͖Ͳ͏ͳΔʁ public class Sample { public static void main(String... args)
{ do { System.out.println("hoge"); } while (false); } } lIPHFz͕ճ͚ͩग़ྗ͞ΕΔ Կى͖ͳ͍ ίϯύΠϧΤϥʔ ࣮ߦ࣌Τϥʔ
࣍ͷίʔυͷಈ͖Ͳ͏ͳΔʁ public class Sample { public static void main(String... args)
{ do { System.out.println("hoge"); } while (false); } } lIPHFz͕ճ͚ͩग़ྗ͞ΕΔ Կى͖ͳ͍ ίϯύΠϧΤϥʔ ࣮ߦ࣌Τϥʔ
public class Sample { public static void main(String... args) {
do { System.out.println("hoge"); } while (false); } } ղઆ EPXIJMFࣄޙධՁ ճॲཧͨ͠ޙʹ݅ࣜΛఆ
ղઆ ॲཧ ݅ XIJMF ॲཧ ݅ EPXIJMF
0CKFDUJWF$ฤ
ୈ
Կ͕ग़ྗ͞ΕΔʁ
Կ͕ग़ྗ͞ΕΔʁ if (@0) { NSLog(@"true"); } else { NSLog(@"false"); }
Կ͕ग़ྗ͞ΕΔʁ if (@0) { NSLog(@"true"); } else { NSLog(@"false"); }
USVF GBMTF
Կ͕ग़ྗ͞ΕΔʁ if (@0) { NSLog(@"true"); } else { NSLog(@"false"); }
USVF GBMTF
ղઆ w @0</4/VNCFSOVNCFS8JUI*OU>ͷ4ZOUBY4VHBS w /4/VNCFSΦϒδΣΫτ w ΦϒδΣΫτͱͯ͠ଘࡏ͢ΔͨΊɺ USVFͱͯ͠ఆ͞ΕΔ w @NOಉ༷
ୈ
Կ͕ग़ྗ͞ΕΔʁ
Կ͕ग़ྗ͞ΕΔʁ [ "hoge", "fuga", null, "foo", "bar" ] TBNQMFKTPO NSArray
*array = ... // JSONΛಡΈࠐΉॲཧ if (array[2]) { NSLog(@"true"); } else { NSLog(@"false"); }
Կ͕ग़ྗ͞ΕΔʁ USVF GBMTF [ "hoge", "fuga", null, "foo", "bar" ]
TBNQMFKTPO NSArray *array = ... // JSONΛಡΈࠐΉॲཧ if (array[2]) { NSLog(@"true"); } else { NSLog(@"false"); }
Կ͕ग़ྗ͞ΕΔʁ USVF GBMTF [ "hoge", "fuga", null, "foo", "bar" ]
TBNQMFKTPO NSArray *array = ... // JSONΛಡΈࠐΉॲཧ if (array[2]) { NSLog(@"true"); } else { NSLog(@"false"); }
ղઆ w /4"SSBZͷίϨΫγϣϯʹOJMΛೖΕΔ͜ͱ͕Ͱ͖ͳ ͍ w େମखஈͱͯ͠/4/VMMͱ͍͏ΫϥεΛ͏ w ͜ͷ࣌BSSBZ<>͔ΒऔΓग़͞ΕΔͷ</4/VMMOVMM>ͱ͍͏ γϯάϧτϯΦϒδΣΫτ w
ΦϒδΣΫτͳͷͰUSVFͱͯ͠ఆ͞ΕΔ
/4/VMMͱOJM NSLog(@"%@", nil); // -> (null) NSLog(@"%@", [NSNull null]); //
-> <null> ྻʹฆΕ͍ͯΔOVMMΑ͘ݟམͱ͕ͪ͠
͜ΜͳΜͬͯͯԿʹͳΔʁ
͜ΜͳΜͬͯͯԿʹͳΔʁ w +BWB w 0$+1 0SBDMFೝఆࢿ֨ Ͱ͜͏͍͏͕ग़͞ΕΔ w ࣮Ͱ͏ҙຯ໓ଟʹແ͍͕ɺ ϨΨγʔͳγεςϜͰۃكʹฆΕࠐΜͰΔ
w ϦʔμϒϧίʔυͬͯͬͯΔʁ
͜ΜͳΜͬͯͯԿʹͳΔʁ w 0CK$ w ҙ֎ͱݟམͱ͕ͪ͠ w ͜ͷखͷޡղ͔ΒੜͣΔόά͕࣮ࡍʹ͋ͬͨ w 4XJGUͷϦϓϨʔεͰఆͱҧ͏ಈ͖Λ͢Δͱ͔ w
ಛʹྻʹฆΕࠐΉOVMM͋Δ͋Δ
͜ΜͳΜͬͯͯԿʹͳΔʁ w ͍ͭͰʹ w ৽ਓݚमͰυϠΕΔ
·ͱΊ w ϨΨγʔݴޠͷཧղϦϓϨʔεͷڧ͍ຯํ w ࢥΘ͵όάΛੜ·ͳ͍ͨΊʹݴޠ༷ͷཧղେ w ࣮ͰΘͳ͍͔ࣝͩΒͬͯܰࢹ͠ͳ͍Α͏ʹ
ྑ͍͓Λʂ✋