Java继承与组合

public class Main {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Person p = new Student();
        System.out.println(p.name);
    }

}
class Person {
    public String name;
    public String sex;
    public short age;
    public Person(){
        name = "John";
        System.out.println("It is a person");
    }
}
class Student extends Person{
    public String name;
    public Student(){
        this.name = super.name;    //利用super引用父类变量
        System.out.println("It is a student");
    }
}

//输出
It is a person
It is a student
John

public class Main {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Person p = new Student();
        p.printName();
        p.printAge();
    }

}
class Person {
    private Pet p = new Pet();
    /*static{
        System.out.println("Person");
    }*/
    public String name;
    public String sex;
    public short age;
    public Person(String name){
        this.name = name;
    }
    public void printName(){
        System.out.println("My name is" + name);
    }
    public static void printAge(){
        System.out.println("This is used to print the people‘s age");
    }
}
class Student extends Person{
    public String name;
    public int age;
    public Student(){
        super("John");
        this.name = super.name;    //利用super引用父类变量
    }
    public static void printAge(){
        System.out.println("This is used to print the student‘s age");
    }
    public void printName(){
        System.out.println("It is used to print the student‘s name");
    }
}

//输出
It is used to print the student‘s name
This is used to print the people‘s age

class Person {
    public String name;
    public Person(String name){
        this.name = name;
    }
    public void printName(){
        System.out.println("My name is" + name);
    }
}
class Student extends Person{
    public Student(){
        super("John");
    }
    public void printName(){
        System.out.println("It is used to print the student‘s name");
    }
}

class Student extends Person{
    public String name;
    public School school;        //组合
    public Student(){
        super("John");
        this.name = super.name;    //利用super引用父类变量
    }
    public void printName(){
        System.out.println("It is used to print the student‘s name");
    }
}
class Person {
    public String name;
    public Person(String name){
        this.name = name;
    }
    public void printName(){
        System.out.println("My name is" + name);
    }
}
class School {
    public String name;
    public String address;
    public void printName(){
        System.out.println("School name:" + name);
    }
    public void printAddress(){
        System.out.println("School address" + address);
    }
}