swift 字符串基础

//

//  main.swift

//  test

//

//  Created by lanou on 16/10/24.

//  Copyright (c) 2016年 lanou. All rights reserved.

//

import Foundation

//字符串拼接

let str = "Hello,world"

var str1 = "WORLD"

var str2 = str +str1

var str3 = str +"world"

var str31 = "\(str) world"

str1 += ",good morning"

println("str31")

println("str2")

println("str3")

println(str1)

//初始化字符串

let str6:String =String(format: "%d + %d = %d", arguments: [1,2,3])

//判断字符前缀

if(str.hasPrefix("Hello")){

    println("YES")

}else{

    println("NO")

}

//判断字符后缀

if(str.hasSuffix("world")){

    println("Yes")

}else{

    println("No")

}

//判断字符是否为空

if str.isEmpty {

    println("Empty")

}else{

    println("not Empty")

}

//判断字符串的长度  character.count     Xcode 7.1  参数4 ：UTF8编码

println(str2.lengthOfBytesUsingEncoding(4))

//字符串大小写转换

println(str.uppercaseString)

println(str1.lowercaseString)

// 字符串的遍历

var st = "Hello,world"

for temp inst{

    println(temp)

}