[4.2循环结构](4.1%E5%BE%AA%E7%8E%AF%E7%BB%93%E6%9E%84.md) [4.3键值循环](4.3%E9%94%AE%E5%80%BC%E5%BE%AA%E7%8E%AF.md) [4.4switch语句](4.4switch%E8%AF%AD%E5%8F%A5.md) [4.5goto语句](4.5goto%E8%AF%AD%E5%8F%A5.md) [4.6break语句](4.5break%E8%AF%AD%E5%8F%A5.md) [4.7continue语句](4.7continue.md)