字符串

字符串

        let str = "叼到飞起来"

        // for循环字符串
        for s in str.characters {
            print(s)
        }

        // 打印字符串的长度
        print(str.characters.count)

        // 转换成OC字符串(as: 类型转换)
        let ocStr = str as NSString
        print(ocStr.length)



        // 字符串拼接
        let firstName = "Jerry"
        let lastName = "Yao"
        let age = 18

        let fullName = firstName + lastName
        print(fullName)

        let desc = "Name is \(firstName) and age is \(age)"
        print(desc)

        // 字符串格式化
        let h = 3
        let m = 4
        let s = 8

        let time = String(format: "%02d:%02d:%02d", h, m, s)
        print(time)