reduce()

func reduce<Result>( _ initialResult: Result, // 결과를 저장할 초기값, 축약 연산의 시작점 _ nextPartialResult: (Result, Self.Element) throws -> Result ) rethrows -> Result

let numbers = [1, 2, 3, 4, 5] let sum = numbers.reduce(0) { (result, number) in result + number } print(sum) // 출력: 15

let numbers = [1, 2, 3, 4, 5] let sum = numbers.reduce(0) { $0 + $1 } print(sum)