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Javascript 9

  • Codility - Max Counters

    ## Max Counters ### ๋ฌธ์ œ ์ˆซ์ž N์ด ์ฃผ์–ด์ง„๋‹ค. ์ด ์ˆซ์ž N์€ ๋ชจ๋“  ์š”์†Œ๊ฐ€ 0์ธ ๊ธธ์ด N์ธ ๋ฐฐ์—ด์„ ์˜๋ฏธํ•œ๋‹ค. ๊ทธ๋ฆฌ๊ณ  ๋ฐฐ์—ด A๊ฐ€ ์กด์žฌํ•œ๋‹ค. ``` ์ˆซ์ž N์ด 5๋กœ ์ฃผ์–ด์ง€๊ณ , ๋ฐฐ์—ด A๋Š” [3, 4, 4, 6, 1, 4, 4] ๋ผ๊ณ  ๊ฐ€์ •ํ•˜์ž. ์ดˆ๊ธฐ ๊ฐ’ [0, 0, 0, 0 0] A[0] = 3, 3๋ฒˆ์งธ (3-1๋ฒˆ์งธ) ์š”์†Œ์˜ ํฌ๊ธฐ๋ฅผ 1 ๋Š˜๋ฆฐ...

    3๋ถ„
  • Codility - Missing Integer

    ## Missing Integer ### ๋ฌธ์ œ ์ฃผ์–ด์ง„ ๋ฐฐ์—ด A์— ๋น ์ ธ ์žˆ๋Š” ๊ฐ€์žฅ ์ž‘์€ ์–‘์˜ ์ •์ˆ˜๋ฅผ ๊ตฌํ•˜์‹œ์˜ค ``` A=[1, 3, 6, 4, 1, 2] ์ด๋ผ๋ฉด ๋‹ต์€ 5 A=[1, 2, 3] ์ด๋ผ๋ฉด ๋‹ต์€ 4 A=[-1, -3] ์ด๋ผ๋ฉด ๋‹ต์€ 1 ``` ### ํ’€์ด ```javascript function solution(A) { // ๋ฐฐ์—ด ๊ธธ...

    1๋ถ„
  • Codility - Distinct

    ## Distinct ### ๋ฌธ์ œ ๋ฐฐ์—ด A์•ˆ์— uniqueํ•œ ์ˆซ์ž๊ฐ€ ๋ช‡ ๊ฐœ ์žˆ๋Š”์ง€ ๋ฆฌํ„ดํ•˜๋ผ. ### ํ’€์ด ```javascript function solution(A) { return [...new Set(A)].length } ``` Set์„ ํ™œ์šฉํ•˜๋ฉด ์‰ฝ๊ฒŒ ํ’€ ์ˆ˜ ์žˆ๋‹ค. Set์ด ์•„๋‹ˆ๋”๋ผ๋„ object๋“ฑ์„ ํ™œ์šฉํ•ด๋ณด๋ฉด ๋œ๋‹ค. https:...

    1๋ถ„
  • Codility - Cyclic Rotation

    ## 2-1 Cyclic Rotation ### ๋ฌธ์ œ ๋ฐฐ์—ด A๊ฐ€ ์ฃผ์–ด์ง€๊ณ  ์ด๋ฅผ K๋ฒˆ ๊ฐ ๋ฐฐ์—ด์˜ ์š”์†Œ๋ฅผ ์˜ค๋ฅธ์ชฝ์œผ๋กœ ์ด๋™์‹œ์ผฐ์„ ๋•Œ, ๊ทธ ๊ฒฐ๊ณผ๋ฅผ ๋ฆฌํ„ดํ•˜์‹œ์˜ค. ``` A = [3, 8, 9, 7, 6] K = 3 [3, 8, 9, 7, 6] -> [6, 3, 8, 9, 7] [6, 3, 8, 9, 7] -> [7, 6, 3, 8, 9] [7, 6, 3, 8...

    1๋ถ„
  • Codility - Odd Occurrences in array

    ## 2-2 Odd Occurrences in array ### ๋ฌธ์ œ ์ˆซ์ž๋กœ ์ด๋ค„์ง„ ๋ฐฐ์—ด์—์„œ ํ™€์ˆ˜ ๋ฒˆ ๋“ฑ์žฅํ•˜๋Š” ์ˆซ์ž๋ฅผ ์ฐพ์•„์„œ ๋ฆฌํ„ดํ•ด๋ผ. ``` A[0] = 9 A[1] = 3 A[2] = 9 A[3] = 3 A[4] = 9 A[5] = 7 A[6] = 9 7์€ ํ•œ๋ฒˆ๋งŒ ๋“ฑ์žฅํ•˜๋ฏ€๋กœ 7์„ ๋ฆฌํ„ดํ•ด์•ผ ํ•œ๋‹ค. ``` ### ํ’€์ด ```javascri...

    1๋ถ„
  • Codility - Genomic Range Query

    ## Genomic Range Query ### ๋ฌธ์ œ DNA๋Š” A, C, G, T๋กœ ๊ตฌ์„ฑ๋˜์–ด ์žˆ๋Š”๋ฐ, ์ด๋Š” ๊ฐ๊ฐ 1, 2, 3, 4๋ฅผ ๊ฐ€๋ฅดํ‚จ๋‹ค. ์ด๋Ÿฌํ•œ DNA๋ฅผ ๋ฆฌํ„ดํ•˜๋Š” S๊ฐ€ ์žˆ๊ณ , ๋ฐฐ์—ด์˜ ๊ธธ์ด๊ฐ€ ๊ฐ™์€ P์™€ Q๊ฐ€ ์žˆ๋‹ค. ``` S=CAGCCTA P=[2, 5, 0] Q=[4, 5, 6] ๊ฐ 0๋ฒˆ์งธ ์š”์†Œ๋Š” 2, 4๋‹ค. 2๋ฒˆ์งธ ~ 4๋ฒˆ์งธ DNA๋Š” GCC...

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  • ์ž๋ฐ”์Šคํฌ๋ฆฝํŠธ ์Šคํ‚ฌ์„ ํ–ฅ์ƒ ์‹œํ‚ฌ 10๊ฐœ์˜ ์งˆ๋ฌธ

    ## ์ž๋ฐ”์Šคํฌ๋ฆฝํŠธ ์Šคํ‚ฌ์„ ํ–ฅ์ƒ ์‹œํ‚ฌ 10๊ฐœ์˜ ์งˆ๋ฌธ [10 JavaScript Quiz Questions and Answers to Sharpen Your Skills](https://typeofnan.dev/10-javascript-quiz-questions-and-answers/) ์˜ ์งˆ๋ฌธ์„ ๋ณด๊ณ , ๋‹ต์— ๋Œ€ํ•œ ํ•ด์„์„ ์ œ๋ฉ‹๋Œ€๋กœ ์จ๋ณด์•˜์Šต๋‹ˆ๋‹ค. ### 1....

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  • ์ž๋ฐ”์Šคํฌ๋ฆฝํŠธ ์ œ๋„ค๋ ˆ์ดํ„ฐ

    ## Generator ์ œ๋„ค๋ ˆ์ดํ„ฐ์˜ ๊ฐœ๋…์— ๋Œ€ํ•ด ์ดํ•ดํ•˜๊ธฐ ์ „์—, ๋จผ์ € ๋ฐ˜๋ณต์ž (Iterator)์— ๋Œ€ํ•ด ์•Œ์•„๋ณด์ž. ### 0. Iterator ๋ฐ˜๋ณต์ž๋Š”, ๋‘๊ฐœ์˜ ์†์„ฑ (`value`์™€ `done`)์„ ๋ฐ˜ํ™˜ํ•˜๋Š” `next()`๋ฉ”์†Œ๋“œ๋ฅผ ์‚ฌ์šฉํ•˜์—ฌ [Iterator protocal](https://developer.mozilla.org/en-US/docs/W...

    4๋ถ„
  • ์ž๋ฐ”์Šคํฌ๋ฆฝํŠธ ๋ฐ์ฝ”๋ ˆ์ดํ„ฐ

    ## ๋ฐ์ฝ”๋ ˆ์ดํ„ฐ ### 0. ์„ค๋ช…์ž ๋ฐ์ฝ”๋ ˆ์ดํ„ฐ์— ๋Œ€ํ•ด ์‹œ์ž‘ํ•˜๊ธฐ ์ „์—, ์„ค๋ช…์ž(Descriptor)์— ๋Œ€ํ•ด ์•Œ์•„๋ณด์ž. ์„ค๋ช…์ž๋ž€, ๊ฐ์ฒด์˜ ํ”„๋กœํผํ‹ฐ๊ฐ€ ์“ฐ๊ธฐ๊ฐ€ ๊ฐ€๋Šฅํ•œ์ง€, ๊ทธ๋ฆฌ๊ณ  ์—ด๊ฑฐ๊ฐ€ ๊ฐ€๋Šฅํ•œ์ง€ ์—ฌ๋ถ€๋ฅผ ๋‚˜ํƒ€๋‚ธ๋‹ค. ๊ทธ๋ฆฌ๊ณ  ์„ค๋ช…์ž๋ฅผ ๊ตฌํ˜„ํ•˜๊ธฐ ์œ„ํ•ด์„œ๋Š”, [Object.getOwnPropertyDescriptor(obj, propName)](https://develo...

    4๋ถ„
  • var let const, ๊ทธ๋ฆฌ๊ณ  ํ˜ธ์ด์ŠคํŒ…

    ## var let const, ๊ทธ๋ฆฌ๊ณ  ํ˜ธ์ด์ŠคํŒ… ### var ์šฐ๋ฆฌ๊ฐ€ ๋ชจ๋‘ ์•„๋Š” `var` ํ‚ค์›Œ๋“œ๋Š” ์•„๋ž˜์™€ ๊ฐ™์€ ํŠน์ง•์„ ๊ฐ€์ง€๊ณ  ์žˆ๋‹ค. 1. ํ•จ์ˆ˜๋ ˆ๋ฒจ ์Šค์ฝ”ํ”„๋ฅผ ๊ฐ€์ง€๊ณ  ์žˆ๋‹ค. ๋Œ€๋ถ€๋ถ„์˜ ํ”„๋กœ๊ทธ๋ž˜๋ฐ ์–ธ์–ด๋“ค์ด ๋ธ”๋ก ๋ ˆ๋ฒจ ์Šค์ฝ”ํ”„๋ฅผ ์‚ฌ์šฉํ•˜๊ณ  ์žˆ์ง€๋งŒ, `var`๋กœ ์„ ์–ธ๋œ ํ‚ค์›Œ๋“œ๋Š” ํ•จ์ˆ˜๋ ˆ๋ฒจ ์Šค์ฝ”ํ”„๋ฅผ ๊ฐ–๋Š”๋‹ค. ```javascript var ...

    6๋ถ„
  • javascript ์ผ๋ฐ˜ ํ•จ์ˆ˜์™€ ํ™”์‚ดํ‘œ ํ•จ์ˆ˜์˜ ์ฐจ์ด

    ES6์—์„œ๋ถ€ํ„ฐ ์ƒ๊ธด `arrow function`์€ ์ผ๋ฐ˜์ ์œผ๋กœ `()=>{}`์˜ ๋ชจ์–‘์„ ํ•˜๊ณ  ์žˆ์œผ๋ฉฐ, ๋™์ž‘๋„ ๋น„์Šทํ•ด๋ณด์ธ๋‹ค. ํ•˜์ง€๋งŒ ์ด ๋‘ ์„ ์–ธ๋ฐฉ์‹์€ ๋‘๊ฐ€์ง€ ๋ถ„๋ช…ํ•œ ์ฐจ์ด๋ฅผ ๊ฐ€์ง€๊ณ  ์žˆ๋‹ค. ํ•˜์ง€๋งŒ ๊ทธ์ „์— this๋ฅผ ์•Œ์•„์•ผ ํ•œ๋‹ค.

    3๋ถ„
  • ์ž๋ฐ”์Šคํฌ๋ฆฝํŠธ์˜ private

    ์ด ๊ธ€์€ [์€๋‹‰์„ ํ–ฅํ•œ ์ž๋ฐ”์Šคํฌ๋ฆฝํŠธ์˜ ์—ฌ์ •](https://meetup.toast.com/posts/228)์„ ์š”์•ฝํ•œ ๊ธ€์ž…๋‹ˆ๋‹ค. ## History ์ž๋ฐ”์Šคํฌ๋ฆฝํŠธ์—์„œ๋Š” ๊ฐ์ฒด์— private ํ•œ ์†์„ฑ์„ ๋งŒ๋“ค ์ˆ˜๊ฐ€ ์—†์—ˆ๋‹ค. ๊ทธ๋ž˜์„œ ๋ณดํ†ต ์ž๋ฐ”์Šคํฌ๋ฆฝํŠธ ๊ฐœ๋ฐœ์ž๋Š” privateํ•œ ๊ฒƒ์ด๋‹ค ๋ผ๋Š” ์•ฝ์†์œผ๋กœ `_` prefix๋ฅผ ๋ถ™์—ฌ์„œ ์‚ฌ์šฉํ•˜๊ณ ๋Š” ํ–ˆ์—ˆ๋‹ค. ```javas...

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