Swift－字符串操作以及运算

/*
1、字符
*/
var c:Character
c = "张"//在swift中字符可以是单个中文,OC中只能是单个英文
var cc:String = "aab张三"
print("1、字符\n\(cc.characters.count)")

/*
2、字符串构造
*/
let str1 = "\n2、字符串构造\nhello,"
let str2 = "world"
let str3 = str1 + str2
print(str3)
var urlStr = "http://www.baidu."
var urlString = "\(urlStr)com"
print(urlString)

/*
3、字符串比较
*/
print("\n3、字符串比较")
let str31 = "hello"
if str31 >= "aello"{
print(str31)
}
let str32 = "Apple"
if str32.hasPrefix("a")
{
print(str32)
}
print(str32.uppercased())//全部大写
print(str32.lowercased())//全部小写

/*
4、数学运算
*/
print("\n4、数学运算")
//let a:UInt8 = 255 + 1//overflow 溢出
let a:UInt8 = 255
let b:UInt8 = 10
//let ab = a+b //运行时报错（溢出）
//print(9 % 2.5)

/*
5、区间运算
闭区间：（a...b）  1...3 -> 1,2,3
半闭区间：（a..<b) 1..<3 -> 1,2
*/
print("\n5、区间运算")
for i in 1..<3{
print(i)
}