Swfit - 字符串的你看我就🐶了

字符串在编程中是形影不离的，懂多点，用起来就方便点。

下面有字符串常用的一系列操作

替换 - 过滤 - 切割 - 拼接

var str = " 🚗 🍎 🚗 🍎 "

//字符串替换操作 -> 把苹果都换成汽车
let filtered = str.stringByReplacingOccurrencesOfString("🍎", withString: "🚗", options: .LiteralSearch, range: nil)
    // = " 🚗 🚗 🚗 🚗 "

//过滤也也一样 -> 比如去掉字符串的所有空格
let filtered2 = str.stringByReplacingOccurrencesOfString(" ", withString: "", options: .LiteralSearch, range: nil)
    // =  "🍎🚗🍎🚗"

//去掉开头和结尾的空白
let newStr = str.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceCharacterSet())
    // = " 🚗 🍎 🚗 🍎"

//切割 -> 返回数组
let splitedArr1 = str.componentsSeparatedByString(" ")
    // = ["", "", "🚗", "🍎", "🚗", "🍎", ""]
let splitedArr2 = str.characters.split{ $0 == " "}.map(String.init)
   // = ["🚗", "🍎", "🚗", "🍎"]

//拼接 数组 -> 字符串
let strGG = ["1","2","3"].joinWithSeparator("-")
//  = "1-2-3"

let str =  ["2","3","4"].reduce("", combine: +) // =  "234"

更多字符串基础操作内容可以看哥这篇 Swift - String 初级用法合集