//: Playground - noun: a place where people can play
import UIKit
// 拼接
var str = "Hello, playground"
str + "hello, swift" // 这样的拼接, str还是没有改变
str
str += "hello, swift"
str
// 比较
var c1 = "abc"
var c2 = "abd"
c1 < c2
var c3 = "abbbb"
c1 > c3
// 前缀和后缀
var chapter = [
"第一章: 1.为你的下一代iOS应用开发做准备",
"第二章: 1.使用xcode7",
"第二章: 2.常量和变量",
"第二章: 3.布尔类型及if语句",
"第二章: 4.元组"
]
var count = 0
for name in chapter {
if (name.hasPrefix("第二章")) {
count++
}
}
print("第二章有\(count)小节")
转载于:https://www.cnblogs.com/Rinpe/p/5050786.html