ELLO의 개발일지

Subject A Subject is a sort of bridge or proxy that is available in some implementations of ReactiveX that acts both as an observer and as an Observable. Because it is an observer, it can subscribe to one or more Observables, and because it is an Observable, it can pass through the items it observes by reemitting them, and it can also emit new items. Subject는 observer와 Observable 모두로 작동하는 일부 Rea..

Single RxJava (and its derivatives like RxGroovy & RxScala) has developed an Observable variant called “Single.” RxJava(및 RxGroovy 및 RxScala와 같은 파생 제품)는 "Single"이라는 Observable 변형을 개발했습니다. A Single is something like an Observable, but instead of emitting a series of values — anywhere from none at all to an infinite number — it always either emits one value or an error notification. Single은 Observ..

Introduction Each language-specific implementation of ReactiveX implements a set of operators. Although there is much overlap between implementations, there are also some operators that are only implemented in certain implementations. Also, each implementation tends to name its operators to resemble those of similar methods that are already familiar from other contexts in that language. Reactive..

Observable In ReactiveX an observer subscribes to an Observable. Then that observer reacts to whatever item or sequence of items the Observable emits. This pattern facilitates concurrent operations because it does not need to block while waiting for the Observable to emit objects, but instead it creates a sentry in the form of an observer that stands ready to react appropriately at whatever futu..

Memory Safety(메모리 안전) By default, Swift prevents unsafe behavior from happening in your code. For example, Swift ensures that variables are initialized before they’re used, memory isn’t accessed after it’s been deallocated, and array indices are checked for out-of-bounds errors. 기본적으로 Swift는 코드에서 안전하지 않은 동작이 발생하는 것을 방지합니다. 예를 들어, Swift는 변수가 사용되기 전에 초기화되고, 할당이 해제된 후 메모리에 액세스되지 않으며, 범위를 벗어난 에러에 대해..

107. Dictionary Dictionary 선언 기본 선언 var a = [String: Int]() var a: [String: Int] = [:] var a: [String: String] = ["name": "Lee", "nickName": "kingkong"] Dictionary 활용 초기화 var dictionary = [String: Int]() if dictionary["count"] == nil { dictionary["count"] = 1 } else { dictionary["count"]! += 1 } /* key에 대한 개수를 세고 싶을 때 값이 없다면(nil) 1, 있다면 += 1 */ 수정 var dictionary: [String: String] = ["name": "Lee..

106. Set Set 선언 기본 선언 var a = Set() var a: Set = [] var a: Set = ["apple", "banana", "orange"] let a: Set = ["apple", "banana", "orange"] 기본 연산 insert(_ newMember: Element) - 새로운 원소를 저장 contains(_ member: Element) - 특정 원소가 있는지 없는지 판별 remove(_ member: Element) - 특정 원소를 삭제 Fundamental Set Operations var a: Set = ["apple", "banana", "orange"] var b: Set = ["a", "banana", "o"] /* union - 합집합(b U a) ..

105. Array 배열 선언 1차원 배열 /* 타입만 설정한 배열 */ let array: [Int] let array: Array /* 빈 값으로 초기화한 배열 */ let array = [Int]() let array: [Int] = [] let array: [Int] = [Int]() let array = Array() let array: Array = [] let array: Array = Array() /* 크기를 고정하고 하나의 값으로 초기화한 배열 */ let array = Array(repeating: 0, count: 5) let array = [Int](repeating: 0, count: 5) /* (문자열도 동일) */ 2차원 배열 /* 타입만 설정한 배열 */ let array:..

104. Strings 문자열 인덱싱 for문 let string = "apple" for index in string.indices { print(string[index]) } 또는 for (index, value) in string.enumerated() { print(index, value) } 또는 string.enumerated().forEach { index, value in print(index, value) } 또는 string.enumerated().forEach { print($0.offset, $0.element) } 직접 접근 let string = "apple" let index = string.index(string.startIndex, offsetBy: 3) /* 3번째 인덱스..

103. Loops for문 범위 연산자 var numberArray = [Int](repeating: 0, count: 5) for i in 0..