package com.oop.demo01;

public class Demo02 {
    public static void main(String[] args) {
        //例項化這個類 new
        //物件型別  物件名 = 物件值；

        Student student = new Student();
        student.say();
    }

    //和類一起載入的
    public  void a(){
        b();
        f();
    }
    //類例項化 之後才會存在
    public void b(){

    }
    public  static void c(){
        d();
    }
    public  static void  d(){

    }
    public void e(){
        f();
    }
    public void f(){

    }
}

package com.oop.demo01;

public class Demo03 {
    public static void main(String[] args) {
        //實際引數和形式引數的型別要對應！
      int add =  Demo03.add(1,2);
        System.out.println(add);
    }

    public static int add(int a, int b){
        return a+b;
    }

package com.oop.demo01;

public class Demo04 {
    public static void main(String[] args) {
        int a = 1;
        System.out.println(a);//1

        Demo04.change(a);

        System.out.println(a);//1
    }

    //返回值為空
    public static void change(int a){
        a = 10;
    }

package com.oop.demo01;

//引用傳遞: 物件，本質還是值傳遞

//物件，記憶體

public class Demo05 {
    public static void main(String[] args) {
        Perosn perosn = new Perosn();

        System.out.println(perosn.name);//null

        Demo05.change(perosn);

        System.out.println(perosn.name);//Leo

    }
    public static void change(Perosn perosn){
        //perosn是一個物件：指向的--> Perosn perosn = new Perosn();這是一個具體的人，可以改變屬性！
        perosn.name = "Leo";
    }


}
class Perosn{
    String name;//null
}

}

}