let  someString        =   "Some      string    literalvalue"
 
 
 
let wiseWords = "\"Imagination is moreimportant than knowledge\" -Einstein" let  dollarSign      =   "\x24"                  //  $,
Unicodescalar U+0024
 
let  blackHeart       =   "\u2665"               //  ,
Unicodescalar U+2665
 
let  sparklingHeart        =  "\U0001F496"           //
 
, Unicode scalarU+1F496

var emptyString = ""                                //
空串初始化
var anotherEmptyString = String()              //  通 过初始化函数初始化
 

if emptyString.isEmpty{
 
println("Nothing to see here")
 
}

var variableString = "Horse" variableString+= " and carriage"
 
 
 
 
let constantString = "Highlander" constantString  += "  and   another

Highlander" //错误
 

字符串插入

let multiplier = 3
 
let message = "\(multiplier) times 2.5 is
\(Double(multiplier) * 2.5)"

字符串长度

使用 countElements函数。

let  unusualMenagerie            =  "Koala     , Snail, Penguin,Dromedary" println("unusualMenagerie                     has
\(countElements(unusualMenagerie))
characters")

比较字符串相等

let quotation = "We're a lot alike, you and I."let sameQuotation = "We're a lot alike, youand I."
 
 
if quotation == sameQuotation {
 
println("These         two       strings      areconsidered equal")
 
}