//: Playground - noun: a place where people can play

import UIKit

var str = "hi"

// 字符串拼接

str += ", rinpe"

str += ", lili"

// 创建一个空的字符串

var nullStr = String()

var nullStr2 = ""

// 判断一个字符串是否为空

nullStr.isEmpty

// 字符串遍历

for string in str.characters {

    string

}

// Charater

var ch:Character = "