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TypeScriptの型定義が JavaScriptのバグを駆逐する
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Tetsuya Negishi
February 22, 2019
Programming
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950
TypeScriptの型定義が JavaScriptのバグを駆逐する
Tetsuya Negishi
February 22, 2019
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Transcript
TypeScriptͷܕఆ͕ٛ JavaScriptͷόάΛۦஞ͢Δ ࠜ؛ప
ࣗݾհ • ࠜ؛ప • ϥϯαʔζגࣜձࣾ • ৽نࣄۀ • ओʹϑϩϯτ·ΘΓ୲ •
ڵຯؔ৺ • React, Vue.js, TypeScript • αʔόʔϨε
ࠓ͢͜ͱ • ৽ϓϩμΫτʹTypeScriptΛಋೖͯ͠ΈͯͲ͏͔ͩͬͨ • TypeScriptͪΌΜͱܕఆٛ͢Ε࠷ߴ • ͋Γ͕ͱ͏TypeScript
ϥϯαʔζͷϑϩϯτΤϯυٕज़ͷมભ 2008 ~ ݱࡏ 2015 ~ ݱࡏ 2018 ~ ݱࡏ
2017 ~ 2018
ϥϯαʔζͷϑϩϯτΤϯυٕज़ͷมભ 2008 ~ ݱࡏ 2015 ~ ݱࡏ 2018 ~ ݱࡏ
2016 ~ 2018
TypeScriptΛͬͯΘ͔ͬͨ͜ͱ ܕఆٛʹΑͬͯόά͕ܹݮ ͪΌΜͱܕఆٛ͠ͳ͍ͱόάΔ
None
JavaScriptͰΑ͘ى͖Δόά
JavaScriptͰΑ͘ى͖Δόά data ʹ number ͷྻΛೖΕΔ → Ұ࣌తʹundefind͕ೖΔύλʔϯ͕͋ͬͨ → <Graph>undefindΛఆ͓ͯ͠ΒͣΤϥʔ ReactͰΓ͕ͪ
Τϥʔ
JavaScriptͰΑ͘ى͖Δόά data ʹ Object ΛೖΕΔ → Ұ࣌తʹundefind͕ೖΔύλʔϯ͕͋ͬͨ → <Graph>undefindΛఆ͓ͯ͠ΒͣΤϥʔ ReactͰͷΤϥʔ΄΅͜ͷύλʔϯͷؾ͕͢Δ
Τϥʔ TypeScriptͰൃੜ͠ͳ͍
TypeScriptͰܕఆٛͨ͠߹
TypeScriptͰܕఆٛͨ͠߹ ? → undefinedΛڐ͢
TypeScriptͰܕఆٛͨ͠߹ propsͷܕ͕ܾ·Δ
TypeScriptͰܕఆٛͨ͠߹ data number[] ͱఆٛ͞Ε͍ͯͨͱ͢Δ
TypeScriptͰܕఆٛͨ͠߹ ͜ͷ࣌Ͱ·ͩΤϥʔ → <Graph>ʹ͢ data ͕ undefinedͰ͋ΔՄೳੑ͕͋Δ
TypeScriptͰܕఆٛͨ͠߹ undefinedͷνΣοΫ Τϥʔ͕ग़ͳ͘ͳΔ
TypeScriptͰܕఆٛͨ͠߹ undefinedͷνΣοΫ Τϥʔ͕ग़ͳ͘ͳΔ
TypeScriptͰܕఆٛͨ͠߹ undefinedͷνΣοΫ Τϥʔ͕ग़ͳ͘ͳΔ όάΛະવʹ͛ͯ࠷ߴ
• ͨͩ͜͠Εܕఆ͕͖ٛͪΜͱ͞Ε͍ͯΔ߹ • ϥΠϒϥϦͰରԠ͍ͯ͠ͳ͍߹ͨ·ʹ͋Δ → any Ͱܕఆٛͯ͠ΓΔ͔͠ͳ͍ → ٯʹόάͷԹচʹͳΓ͍͢ Graph͕ܕఆٛ͞Ε͍ͯͳ͍ͱΤϥʔ͕ग़ͳ͍
Enjoy TypeScript!