Java类属性的私有化

Java类属性的私有化

 1、创建一个students类

public class students{

  //students类的属性
  
  private String name;
  
  private int age;
  
  private String gender;
  
  //students类的方法
  
  public students(){
  
   //默认方法
   
  }
  public students(String name,int age,String gender){
  
   //students类的构造方法
   
   this.name = name ;
   this.age = age ;
   this.gender = gender ;
   
  }
  
  //students的get方法获取属性值
  
  public String getName(){
   
   return this.name;
   
  }
  
  public int getAge(){
      
   return this.age;
   
  }
  
  public String getGender(){
   
   return this.gender;
   
  }
  
  //students的set方法对属性进行赋值
  
  public void setName(String name){
   
   this.name = name ;
  }
  public void setAge(int age){
  
  //对age进行范围圈定和判断
  
   if(age>45 || age<15){
    this.age=18;
   }else{
    this.age = age ;
   }
   
  }
  public void setGender(String gender){
   
   this.gender = gender ;
  }
 }

public class students{

  //students类的属性
  
  private String name;
  
  private int age;
  
  private String gender;
  
  //students类的方法
  
  public students(){  //无参数构造方法，方法名是class类名

//默认方法
   
  }
  public students(String name,int age,String gender){  //有参构造方法，方法名是class类名
  
   //students类的构造方法
   
   this.name = name ;
   this.age = age ;
   this.gender = gender ;
   
  }
  
  //students的get方法获取属性值
  
  public String getName(){
   
   return this.name;
   
  }
  
  public int getAge(){
      
   return this.age;
   
  }
  
  public String getGender(){
   
   return this.gender;
   
  }
  
  //students的set方法对属性进行赋值
  
  public void setName(String name){
   
   this.name = name ;
  }
  public void setAge(int age){
  
  //对age进行范围圈定和判断
  
   if( age> 45 || age<15){
    this.age=18;
   }else{
    this.age = age ;
   }
   
  }
  public void setGender(String gender){
   
   this.gender = gender ;
  }
 }

 

2、创建一个studentsDemo测试类

public class studentsDemo {
 public static void main(String[] args) {
 
  //实例化对象
  
  students st = new students() ;
      
//  st.name="小明";
//  st.age=12;
//  st.gender="男";
  
//  System.out.println(st.name+"\n"+st.age+"\n"+st.gender+"\n");
  
  st.setName("小虎");
  st.setAge(14);
  st.setGender("男");
  System.out.println(st.getName()+"\n"+st.getAge()+"\n"+st.getGender()+"\n");
 }
}

输出结果：
小虎
18
男