July 2017
Beginner to intermediate
464 pages
10h 38m
Korean
Content preview from 러닝 자바스크립트: ES6로 제대로 입문하는 모던 자바스크립트 웹 개발
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91
3
장
리터럴과 변수, 상수, 데이터 타입
3.11
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과
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과
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는 자바스크립트의 특별한 타입입니다.
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이 가질 수 있는 값은
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하
나뿐이며,
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가 가질 수 있는 값도
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하나뿐입니다.
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과
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는 모
두 존재하지 않는 것을 나타냅니다. 그리고 이 둘을 서로 다른 데이터 타입으로 분리한 것은 끝
없는 혼란을 낳았고, 특히 초보자들이 고생하고 있습니다.
일반적인 규칙을 제시한다면,
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은 프로그래머에게 허용된 데이터 타입이며
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는
자바스크립트 자체에서 사용한다고 기억하십시오. 이 규칙이 강제는 아닙니다. 프로그래머도
언제든
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값을 사용할 수는 있지만, 꼭 필요할 때만 사용하도록 주의해야 합니다. 필
자가 변수에 직접
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를 할당하는 경우는, 아직 값이 주어지지 않은 변수의 동작을 고의
로 흉내 내야 할 때뿐입니다. 변수의 값을 아직 모르거나 적용할 수 없는 경우에는 대부분
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이 더 나은 선택입니다. 사소한 것에 지나치게 신경 쓰는 것처럼 보일 테고, 어떤 면에서는 실
제로 그렇기도 합니다. 초보 프로그래머들은 불확실할 때는
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을 사용하라고 배우니까요. 변
수를 선언하기만 하고 명시적으로 값을 할당하지
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.