如何在不使用swift数组的情况下获取字符串的最后一个字符？

Question

我有一根绳子

let stringPlusString = TextBoxCal.text

我想得到最后一个字符stringPlusString我不想在java上使用数组charAt但我在swift上找不到这个关键字

Answer 1

使用last得到最后Character

对于Swift 4:

let str = "hello world"
let lastChar = str.last!   // lastChar is ""

对于Swift 2和Swift 3:

let str = "hello world"
let lastChar = str.characters.last!   // lastChar is ""

对于Swift 1.2:

let str = "hello world"
let lastChar = last(str)!   // lastChar is ""

订阅String以获取最后一个Character

这适用于Swift 3和Swift 4:

let str = "hello world"
let lastChar = str[str.index(before: str.endIndex)]   // lastChar is ""

对于Swift 1.2和Swift 2:

let str = "hello world"
let lastChar = str[str.endIndex.predecessor()]   // lastChar is ""

Answer 2

斯威夫特4:

首先是一些char最后一些char

let strOSName = "mac operating system"
print(strOSName.prefix(3))       //first char. o/p:  MAC
print(strOSName.suffix(6))       //last char.  o/p:  system

Answer 3

" 没有在swift上使用Array"

干得好:

var text = "Lorem ipsum"
var lastChar = text.substringFromIndex(text.endIndex.predecessor())