Question

我有以下Obj-c声明：

string = [string substringFromIndex:(range.location + range.length)];

它的Swift等同于什么？

Answer 1

您应该使用substring(from:)：

var string = "Hello World"

string = string.substring(from: string.index(string.startIndex, offsetBy: 6))

print(string) // "World"

此外，您可能希望使用substring(to:)：

let hello = string.substring(to: string.index(string.startIndex, offsetBy: 5))

print(hello) // "Hello"

有关String.Index的详细信息，请查看此question/answer。

Answer 2

如果您不想使用子字符串：

let string = "abcdefghijklm"
let startPoint = 2
let length = 5

let startIndex = string.index(string.startIndex, offsetBy: startPoint)
let endIndex = string.index(startIndex, offsetBy: length)

let result = string[startIndex ..< endIndex]
print(result)         // cdefg

Swift - sum range.location和range.length

2 个答案: