java中的继承之间的数据访问

继承后的成员变量和方法访问都是就近原则：先从本类找找不到去父类找，找不到报错

继承后的构造器；子类的构造器默认会先访问父类的无参构造器再执行自己的构造器，因为继承的前提是父类必须存在，继承是继承父类的属性和行为的，而父类构造器是对父类进行附初始值的，所以执行子类构造器时父类构造器要先于子类的构造器被执行

 

public class Dome_1 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Student student = new Student(18,"香茗","女");
        student.show();

    }

}
class Student extends People{
    public Student(int age,String name,String sex)
    {
        super(age,name,sex);
    }
    public void show()
    {
        System.out.printf("学生信息:age:%d\tname:%s\tsex:%s\n",getAge(),getName(),getSex());
    }
}
class People{
    private int age;
    private String name;
    private String sex;
    public People(int age,String name,String sex)
    {
        this.age = age;
        this.name = name;
        this.sex = sex;
    }
    public void setAge(int age)
    {
        this.age = age;
    }
    public int getAge()
    {
        return this.age;
    }
    public void setName(String name)
    {
        this.name = name;
        
    }
    public String getName()
    {
        return this.name;
    }
    public void setSex(String sex)
    {
        this.sex = sex;
    }
    public String getSex()
    {
        return this.sex;
    }
}

图解