是否可以创建倒置的Range
?
我的意思是从99变为1,而不是相反。我的目标是将值从99迭代到1。
这不会编译,但是应该可以让您了解我要执行的操作:
for i in 99...1{
print("\(i) bottles of beer on the wall, \(i) bottles of beer.")
print("Take one down and pass it around, \(i-1) bottles of beer on the wall.")
}
谁是Swift
中最简单的方法?
您可以在符合stride(through:by:)
协议的任何内容上使用stride(to:by:)
或Strideable
。第一个包含列出的值,第二个在它之前停止。
示例:
for i in 99.stride(through: 1, by: -1) { // creates a range of 99...1
print("\(i) bottles of beer on the wall, \(i) bottles of beer.")
print("Take one down and pass it around, \(i-1) bottles of beer on the wall.")
}
您也可以使用reversed()
:
for i in (1...99).reversed() {
print("\(i) bottles of beer on the wall, \(i) bottles of beer.")
print("Take one down and pass it around, \(i-1) bottles of beer on the wall.")
}