Swift入门之三 [字符串和字符: Strings and C

GitHub Demo: https://github.com/BaHui/BHSwifter

1. 初始化字符串

    let string1 = ""
    let string2 = String()
    print(string1, string2)

2. 字符串的判断是否为空

    let emptyString = ""
    if emptyString.isEmpty {
      print("字符串为空") // 输出: 字符串为空
    } else {
      print("字符串不为空")
    }

3. 通过for-in循环来遍历字符串

    let fullString = "QiaoBaHui"
    for subChar in fullString {
      print(subChar)  // 输出: Q i a o B a H u i
    }
    

4. 连接字符串和字符

    let firstName = "BaHui·"
    let lastName = "Qiao"
    print(firstName + lastName) // 输出: BaHui·Qiao
    

5. 前缀/后缀相等

    let content = "qiaobahui"
    if content.hasPrefix("qiao") {
      print(content.prefix(4)) // 输出: qiao
    }
    
    if content.hasSuffix("hui") {
      print(content.suffix(3)) // 输出: hui
    }