值类型：字符串，数组，字典，数字
引用类型:Class
字符串
let email="swift@163.com"
let range=email.range(of: "@")!
//拿到开始位置
let suffix=email.substring(from: range.upperBound)
//拿到结束位置
let prefix=email.substring(to: range.lowerBound)
//获取从开头到@前面的位置
let newRange=Range(uncheckedBounds: (email.startIndex,range.lowerBound))
print(email[newRange])//输出这一段的信息
//获取从@到结尾的位置
let oldRange=Range(uncheckedBounds: (range.upperBound,email.endIndex))
print(email.characters.count)
//输出这一段的信息
print(email[oldRange])
数组初始化
class SwiftClass: NSObject {
@objc(foo)
func foo()
{
//初始化一个数组
let titles:[String]=["发现音乐","我的音乐","朋友","账号"]
//初始化一个数组
let emptyArray=[String]()
//重复发现映月这个词4次初始化一个这样的数组
let a = Array(repeating: "发现映月", count: 4)
//将数组a和数组titlesp拼接成一个数组
let b=a+titles
print(b)
}
}
Array遍历
//普通的数组遍历
for title in titles{
print(title)
}
//带下标的数组遍历
for (index,title) in titles.enumerated() {
print(index,title)
print(titles[index])
}
