forEach

func forEach(_ body: (Self.Element) throws -> Void) rethrows

arr.forEach{} 배열 순회

let numberWords = ["one", "two", "three"]
for word in numberWords {
    print(word)
}
// Prints "one"
// Prints "two"
// Prints "three"

//위와 같은 결과
numberWords.forEach { word in print(word)
}