class Person{
    private String name ;
     private int age ;
           public void setName(String n){
             name = n ;
  }
      public void setAge(int a ) {
          if (a >=0 && a < 250 )
                  age = a;
        }
      public  String getName(){
      return  name ;
      }
      public   int getAge(){
          return  age;
    }
          public   void  tell (){
      System.out.println("姓名:"+name+"年龄："+age);
 }
}
      public class TestDemo{
       public  static void main (String args [])
             Person per = new Person();
             per.setName("张三");
             per.set Age(-20);
           per.tell();
    }
}