Java基础_内存分析_分析代码

public class Person{

      

       intid;

       intage;

      

       Person(int_id,int _age) {

              this.id = _id;

              this.age = _age;

       }

      

       publicstaticvoid main(string[] args) {

              Person p = new Person(1, 30);

       }

}

 

 

public class TestBirthday{

 

       public static void main(string[] args) {

              TestBirthday test =new TestBirthday();//1

              intdate = 9;//2

              Birthday d1 = new Birthday(7, 7, 1970);//3

              Birthday d2 = new Birthday(1, 1, 2000);//4

              test.change1(date);//5

              test.change2(d1);//6

              test.change3(d2);//7

              System.out.println("date = " + date);

              d1.display();

              d2.display();

       }

      

       voidchange1(int i) {

              i = 1234;

       }

      

       void change2(birthday b) {

              b = newbirthday(22, 2, 2004);

       }

 

       void change3(birthday b) {

              b.setday(22);

       }

 

}

 

class Birthday {

      

       intyear;

       intmonth;

       int day;

      

       Birthday(int_day,int _month,int_year) {

              year =_year;

              month =_month;

              day =_day;

       }

      

       voidsetyear(int _year) {

              year =_year;

       }

      

       voidsetmonth(int _month) {

              month =_month;

       }

      

       voidsetday(int _day) {

              day =_day;

       }

      

       intgetyear() {

              returnyear;

       }

      

       intgetmonth() {

              returnmonth;

       }

      

       intgetday() {

              returnday;

       }

      

       voiddisplay() {

              System.out.println(year +"-" + month + "-" +day);

       }

}

 

 

publicclassCat {

 

       privatestaticintsid =0;

       privateStringname;

       intid;

      

       Cat(String name) {

              this.name = name;

              id =sid++;

       }

      

       publicvoid info() {

              System.out.println("My name is " +name + " No." + id);

       }

      

       publicstaticvoid main(String[] args) {

              Cat.sid =100;//1

              Cat mimi = new Cat("mimi");//2

              Cat pipi = new Cat("pipi");//3

              mimi.info();

              pipi.info();

       }

 

}