Question

我是Swift的初学者，试图解决循环挑战中的“墙上的99瓶啤酒”。关于这个挑战，我有两个问题。

在下面的代码中，我不明白第二个输入“ totalNumberOfBottles”代表什么。调用函数beerSong（）时，我们不会打印或调用此参数，而只会引用forThisManyBottles。它代表什么？它仅仅是forThisManyBottles的另一个副本吗？因此，在for循环中，由于我为瓶子输入的示例编号为5，因此其表示方式等同于：

for number in (1...forThisManyBottles).reversed() {
}

我曾尝试用Swift编程语言完成对Google的类似案例；但是，其中一个是处理case和switch语句的，因此不符合我现在在课程中要学习的逻辑。



func beerSong(forThisManyBottles totalNumberOfBottles : Int) -> String {

    var lyric : String = ""

    for number in (1...totalNumberOfBottles).reversed() {
        let newLine : String = "\n\(number) bottles of beer on the wall, \(number) bottles of beer. \nTake one down and pass it around, \(number - 1) bottles of beer on the wall.\n"
        let oneLine : String = "\n\(number) bottle of beer on the wall, \(number) bottle of beer. \nTake one down and pass it around, no bottles of beer on the wall.\n"
        let twoLine: String = "\n\(number) bottles of beer on the wall, \(number) bottles of beer. \nTake one down and pass it around, \(number-1) bottle of beer on the wall.\n"

        if number == 1 {
            lyric += oneLine
        }
        else if number == 2 {
            lyric+=twoLine
        }
        else {
            lyric += newLine

        }

    }
    lyric += "\nNo more bottles of beer on the wall, no more bottles of beer. \nGo to the store and buy some more, \(totalNumberOfBottles) bottles of beer on the wall.\n"

    return lyric

}
print(beerSong(forThisManyBottles: 5))
)


//The output of my code is as follows:

//5 bottles of beer on the wall, 5 bottles of beer. 
//Take one down and pass it around, 4 bottles of beer on the wall.

//4 bottles of beer on the wall, 4 bottles of beer. 
//Take one down and pass it around, 3 bottles of beer on the wall.
//3 bottles of beer on the wall, 3 bottles of beer. 
//Take one down and pass it around, 2 bottles of beer on the wall.

//2 bottles of beer on the wall, 2 bottles of beer. 
//Take one down and pass it around, 1 bottle of beer on the wall.

//1 bottle of beer on the wall, 1 bottle of beer. 
//Take one down and pass it around, no bottles of beer on the wall.

//No more bottles of beer on the wall, no more bottles of beer. 
//Go to the store and buy some more, 5 bottles of beer on the wall.

此功能参数输入代表什么？

0 个答案: