
p.p1 { margin: 0.0px 0.0px 0.0px 0.0px; font: 13.0px Menlo; color: #4dbf56 }
p.p2 { margin: 0.0px 0.0px 0.0px 0.0px; font: 13.0px Menlo; color: #ffffff; min-height: 15.0px }
p.p3 { margin: 0.0px 0.0px 0.0px 0.0px; font: 13.0px Menlo; color: #ffffff }
p.p4 { margin: 0.0px 0.0px 0.0px 0.0px; font: 13.0px Menlo; color: #e44347 }
p.p5 { margin: 0.0px 0.0px 0.0px 0.0px; font: 13.0px "PingFang SC"; color: #4dbf56 }
p.p6 { margin: 0.0px 0.0px 0.0px 0.0px; font: 13.0px Menlo; color: #93c96a }
p.p7 { margin: 0.0px 0.0px 0.0px 0.0px; font: 13.0px Menlo; color: #00afca }
span.s1 { }
span.s2 { color: #c2349b }
span.s3 { color: #ffffff }
span.s4 { font: 13.0px Menlo }
span.s5 { color: #e44347 }
span.s6 { color: #00afca }
span.s7 { color: #93c96a }
span.s8 { color: #8b84cf }
span.s9 { font: 13.0px "PingFang SC" }
span.s10 { font: 13.0px "PingFang SC"; color: #e44347 }
span.s11 { font: 13.0px "Apple Color Emoji"; color: #e44347 }
span.s12 { color: #4dbf56 }
span.s13 { font: 13.0px "PingFang SC"; color: #4dbf56 }
//: Playground - noun: a place where people can play
import UIKit
var str = "Hello, playground"
//字符串
//空字符串
var emptyString = ""
var emptyString2 = String ()
//空字符串的判断
emptyString.isEmpty
str.isEmpty
let mark = "!!!"
str + mark
str
str += mark
str
//
let name = "liuyubobobo"
let age = 16
let height = 1.78
let s = "My name is \(name). I'm \(age) years old . I'm \(height) meter tall."
print(s)
//
for c in str.characters {
print(c)
}
//字符
str
let mark:Character = "!"
str.append(mark)
str
//string.characters
let englishLetter:Character = "a"
let chineseLetter:Character = "幕"
let dog:Character = "