๐Ÿ‘ฉ‍๐Ÿ’ป๊ฐœ๋ฐœ_TIL/์ž๋ฃŒ 4

[์ž๋ฐ”์Šคํฌ๋ฆฝํŠธ] reduce ๋ฉ”์„œ๋“œ ๊ฐœ๋… ์ •๋ฆฌ ๋ชจ์Œ

https://bit.ly/35eQww5 (JavaScript) map, reduce ํ™œ์šฉํ•˜๊ธฐ - ํ•จ์ˆ˜ํ˜• ํ”„๋กœ๊ทธ๋ž˜๋ฐ ์•ˆ๋…•ํ•˜์„ธ์š”. ์ด๋ฒˆ ์‹œ๊ฐ„์—๋Š” map๊ณผ reduce ๋ฉ”์„œ๋“œ์— ๋Œ€ํ•ด ์•Œ์•„๋ณด๊ฒ ์Šต๋‹ˆ๋‹ค. ๋ฐฐ์—ด์— ์žˆ๋Š” ๋ฐ”๋กœ ๊ทธ map๊ณผ reduce ๋งž์Šต๋‹ˆ๋‹ค. ๋งŽ์€ ๋ถ„๋“ค์ด forEach๋Š” ์‚ฌ์šฉํ•˜์‹œ๋Š”๋ฐ map๊ณผ reduce๋Š” ์ž˜ ์•ˆ ์“ฐ์‹œ๋”๋ผ๊ณ ์š”. ๊ทธ๋ฆฌ๊ณ  redu www.zerocho.com MDN ๋ฌธ์„œ์—์„œ ์„ค๋ช…ํ•˜๋Š” reduce ๋ฉ”์„œ๋“œ ๊ฐœ๋… Array.prototype.reduce() - JavaScript | MDN reduce() ๋ฉ”์„œ๋“œ๋Š” ๋ฐฐ์—ด์˜ ๊ฐ ์š”์†Œ์— ๋Œ€ํ•ด ์ฃผ์–ด์ง„ ๋ฆฌ๋“€์„œ(reducer) ํ•จ์ˆ˜๋ฅผ ์‹คํ–‰ํ•˜๊ณ , ํ•˜๋‚˜์˜ ๊ฒฐ๊ณผ๊ฐ’์„ ๋ฐ˜ํ™˜ํ•ฉ๋‹ˆ๋‹ค. developer.mozilla.org https://bit.ly/33Ijpk7..

[์ž๋ฐ”์Šคํฌ๋ฆฝํŠธ] ๋ฐฐ์—ด์˜ ํŠน์ • ๊ฐ’์„ ์ฐพ๋Š” ๋ฉ”์„œ๋“œ ์ •๋ฆฌ ๋ชจ์Œ

1. find vs findIndex vs indexOf https://bit.ly/3Awj1RK ๋ฐฐ์—ด ๋‚ด์žฅํ•จ์ˆ˜ (indexOf / findIndex / find) indexOf ๋Š” ๋ฐฐ์—ด์—์„œ ์›ํ•˜๋Š” ํŠน์ • ํ•ญ๋ชฉ์ด ๋ฐฐ์—ด์˜ ๋ช‡๋ฒˆ์งธ ์›์†Œ์ธ์ง€ ์ฐพ์•„ index๋ฅผ ๋ฆฌํ„ดํ•ด์ฃผ๋Š” ํ•จ์ˆ˜. (๋งŒ์•ฝ์— ๋ชป์ฐพ์œผ๋ฉด -1 ๋ฆฌํ„ด)๋งŒ์•ฝ ์œ„์—์„œ ์ฒ˜๋Ÿผ ์ฐพ๊ณ ์žํ•˜๋Š” ๊ฒƒ์ด boolean, ์ •์ˆ˜, ๋ฌธ์ž์—ด... ์ด๋ฉด ์œ„์™€ ๊ฐ™์ด velog.io find ๊ฐœ๋… findIndex ๊ฐœ๋… indexOf ๊ฐœ๋…

[์ž๋ฐ”์Šคํฌ๋ฆฝํŠธ] ํ—ท๊ฐˆ๋ฆฌ๋Š” ๋ฐ˜๋ณต๋ฌธ/๋ฉ”์„œ๋“œ ๋น„๊ต ๋ชจ์Œ

1. for in ๋ฐ˜๋ณต๋ฌธ vs for of ๋ฐ˜๋ณต๋ฌธ https://bit.ly/3rN3ed5 for ...in, for ...of ์ฐจ์ด ์ž์ฃผ ํ—ท๊ฐˆ๋ฆฌ๋Š”๊ฒŒ ์žˆ์–ด์„œ ํ•œ๋ฒˆ ํฌ์ŠคํŒ…ํ•ด๋ด…๋‹ˆ๋‹ค.๋ฐ”๋กœ ๋ฐ˜๋ณต๋ฌธ ์ค‘์— ES6 ๋ถ€ํ„ฐ ์ถ”๊ฐ€ ๋œfor ...infor ...of์ž…๋‹ˆ๋‹ค.๋‘˜๋‹ค ๋ฐ˜๋ณต๋ฌธ์œผ๋กœ ์‚ฌ์šฉ ๋˜๋Š”๋ฐ์š” ํ•˜๋‚˜๋Š” ๊ฐ์ฒด๋ฅผ ํƒ์ƒ‰ํ•˜๊ณ  ๋‚˜๋จธ์ง€ ํ•˜๋‚˜๋Š” ๋ฐฐ์—ด ์š”์†Œ๋ฅผ ํƒ์ƒ‰ velog.io https://bit.ly/3FXUNRn Iteration (2) for in๋ฌธ, for of๋ฌธ์˜ ์ฐจ์ด์  for ...in๋ฌธ๊ณผ for ...of ๋ฌธ์€ ์–ธ๋œป ๋ณด๋ฉด ๋‘˜๋‹ค ๊ฐ์ฒด ๊ธธ์ด๋งŒํผ ์ˆœํšŒ๋ฅผ ๋ฐ˜๋ณตํ•˜๊ธฐ ๋•Œ๋ฌธ์— ๋น„์Šทํ•ด๋ณด์ธ๋‹ค. ๊ทธ๋ž˜์„œ ์ž๊พธ ์‚ฌ์šฉํ•  ๋•Œ๋งˆ๋‹ค ํ—ท๊ฐˆ๋ฆฌ๊ธฐ๋„ ํ•ด์„œ ๋‹ค์‹œ ํ•œ๋ฒˆ ์ œ๋Œ€๋กœ ์ •๋ฆฌ๋ฅผ ํ•ด๋‘๋ ค๊ณ  ํ•œ๋‹ค. for …in ๋ฌธ joooing.tistory.com ..

[๋ฆฌ์•กํŠธ]์นดํ…Œ๊ณ ๋ฆฌ ํ•„ํ„ฐ๋ง ๋ฒ„ํŠผ ๊ตฌํ˜„์— ์ฐธ๊ณ ํ•œ ์ž๋ฃŒ

https://www.youtube.com/watch?v=gPH7sCyXFb4&t=1430s ๐Ÿ˜Ž๋ฌด์—‡์ด ์™œ ํ•„์š”ํ–ˆ๋‚˜? ๊ฐœ์ธ ํ”„๋กœ์ ํŠธ๋ฅผ ์ง„ํ–‰ํ•˜๋ฉด์„œ,์นดํ…Œ๊ณ ๋ฆฌ ํ•„ํ„ฐ ๊ธฐ๋Šฅ์„ ๊ตฌํ˜„ํ•  ํ•„์š”๊ฐ€ ์žˆ์—ˆ์Šต๋‹ˆ๋‹ค. '์ƒ์˜', 'ํ•˜์˜' ์ฒ˜๋Ÿผ ์นดํ…Œ๊ณ ๋ฆฌ ๋ณ„๋กœ ๋ฒ„ํŠผ์„ ๋งŒ๋“ค์–ด์„œ ๋ฒ„ํŠผ์„ ํด๋ฆญํ•˜๋ฉด ํ•ด๋‹นํ•˜๋Š” ์ƒํ’ˆ๋งŒ ๋ณด์—ฌ์ฃผ๋Š” ์ปดํฌ๋„ŒํŠธ๋ฅผ ๋งŒ๋“œ๋Š” ๊ฒƒ์ด ๋ชฉํ‘œ์˜€์Šต๋‹ˆ๋‹ค. ๐Ÿ˜Ž์–ด๋–ป๊ฒŒ ์ฐพ์•˜๋‚˜? ์šฐ์„  '๋ฆฌ์•กํŠธ ํ•„ํ„ฐ๋ง ๋ฒ„ํŠผ ๊ตฌํ˜„' ๊ฐ™์€ ํ‚ค์›Œ๋“œ๋กœ ๊ตฌ๊ธ€๋ง์„ ํ–ˆ์Šต๋‹ˆ๋‹ค. ์•„์‰ฝ์ง€๋งŒ ๊ตญ๋‚ด ๋ฌด๋ฃŒ ์ž๋ฃŒ ์ค‘์—์„œ๋Š” ๋”ฑ ์ œ๊ฒŒ ํ•„์š”ํ•œ ์ž๋ฃŒ๋ฅผ ์ฐพ๊ธฐ ํž˜๋“ค์—ˆ์Šต๋‹ˆ๋‹ค. ๊ทธ๋ž˜์„œ 'react filtering by category'๋ผ๋Š” ํ‚ค์›Œ๋“œ๋กœ Youtube๋กœ ๊ฒ€์ƒ‰ํ•˜๋‹ˆ, ๋‹คํ–‰ํžˆ ์›ํ•˜๋Š” ์˜์ƒ์ด ๊ฝค ๋งŽ์ด ๋‚˜์™”์Šต๋‹ˆ๋‹ค. ๊ทธ ์ค‘์—์„œ ๊ฐ€์žฅ ์ตœ๊ทผ์— ์—…๋กœ๋“œ๋œ ์˜์ƒ์„ ๋ณด๋ฉด์„œ ๊ฐœ๋…์„ ์ตํ˜”์Šต๋‹ˆ๋‹ค. ๐Ÿ˜Ž๋ฌด์—‡์„ ์•Œ๊ฒŒ ..

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