// 使用 map() 來篩選出結果
var numberArray4 = [1, 2, 3, 4, 5, 6]
let result3 = numberArray4.map { (i) -> Int in
    return i * 2
}
print("\(result3)") // [2, 4, 6, 8, 10, 12]

var word2Array = ["A", "B", "C"]
let result4 = word2Array.map { (w) -> String in
    let fruitDic: [String: String] = ["A": "Apple", "B": "Banana", "C": "Cherry"]
    return fruitDic[w]!
}
print("\(result4)") // ["Apple", "Banana", "Cherry"]