类与对象.

package com.demo;

      public class Student {  

          String name;  

          char sex;   

          int age;  

}

 

package com.demo;

      public class StudentTest {

          public static void main(String[] args) {  

             Student wangstu=new Student();   

             wangstu.name="王洪涛";   
             wangstu.age=18;  

             wangstu.sex='女';  

             wangstu.showStudent();   

    }

}

 

 

package com.demo;

     import java.util.Scanner;

        public class PersonTest {  

           public static void main(String[] args) {   

              Person person=new Person();        

              person.show();  

     }

}

protected:受保护的
  private：私有的
  public：公共的
  访问级别

 

package com.demo;

     import java.util.Scanner;

       public class Person {

          public String name;

          public int age;    

           /**  

           * 用来循环接收用户输入，然后判断年龄  

           */    

           /**  

          * 如果类和属性还有方法不添加访问修饰符，那么默认是？  

          * 默认是public  

          */  

          public void show(){  

                     Scanner input=new Scanner(System.in);     

                     System.out.println("请输入姓名：");  

                     name=input.next();        

                     //1.循环   

                    while(!name.equals("n")){  

                               System.out.println("请输入年龄：");  

                                age=input.nextInt();  

                     //2.判断   

                     if(age>=18&&age<=60){    

                               System.out.println("门票20元");  

                       }else{     

                               System.out.println("门票免费");   

                       }   

                        System.out.println("请输入姓名：");   

                       name=input.next();    

                       }  

                        System.out.println("程序结束！");

      }

  }