小编ysh*_*lov的帖子

所以

split("There are fourty-eight characters in this string", 20)

应该回来

["There are fourty-eig", "ht characters in thi","s string"]

如果我使currentIndex = string.startIndex,然后尝试进一步提前()它比string.endIndex,我得到"致命错误:不能增加endIndex"之前我检查我的currentIndex <string.endIndex所以下面的代码没有'工作

var string = "12345"
var currentIndex = string.startIndex
currentIndex = advance(currentIndex, 6)
if currentIndex > string.endIndex {currentIndex = string.endIndex}