Q1.
Car.java 필드 -String model, String color, int year, booleans isNewCar
메소드 - Constructor, output
CarMain.java
★
생성자(모델, 색상, 연식) / 생성자(모델, 색상)
Calendar calendar = Calendar.getInstance();
calendar.get(Calendar.YEAR);
Q2.
Song.java 필드 - String title, String country
메소드 - Constructor, output
Singer.java 필드 - String name, Song song
메소드 - Constructor, setSong(s), output
SingerSongMain.java
Q3.
Grade.java 필드 - int kor, int eng, int mat, double average, char grade
메소드 - Constructor, getAverage(평균을 리턴), getGrade(학점을 리턴)
Student.java 필드 - String name, String dept, Grade grade
메소드 - Constructor, output
StudentGradeMain.java
Q4.
Coordinate.java 필드 - int x, int y
메소드 - Constructor, output
Circle.java 필드 - Coordinate center, double radius
메소드 - Constructor, output
Ring.java 필드 - Circle inner, Circle outer
메소드 - Constructor, output
CoordinateCircleRingMain.java
package org.joonzis.test;
import java.util.Calendar;
public class Car {
// 필드
String model;
String color;
int year;
boolean isNewCar;
// 메소드
public Car() {}
public Car(String m, String c, int y) {
model=m;
color=c;
year=y;
}
public Car(String m, String c) {
model=m;
color=c;
Calendar calendar = Calendar.getInstance();
year=calendar.get(Calendar.YEAR);
if(year>=2022) {
isNewCar=true;
}else{
isNewCar=false;
}
}
void output(){
System.out.println("차 모델:"+model);
System.out.println("차 색깔:"+color);
System.out.println("차 연식:"+year);
System.out.println(isNewCar? "새 차":"오래된 차");
}
}
package org.joonzis.test;
public class CarMain {
public static void main(String[] args) {
Car c1 = new Car();
Car c2 = new Car();
Car c3 = new Car();
System.out.println("~~~~~~~~~~");
c1.output();
System.out.println("~~~~~~~~~~");
c2.output();
System.out.println("~~~~~~~~~~");
c3.output();
}
}
package org.joonzis.test;
public class Circle {
Coordinate center;
double radius;
public Circle() {}
public Circle(Coordinate center, double radius) {
this.center = center;
this.radius = radius;
}
void output() {
System.out.println("반지름 : " + radius);
center.output();
}
}
package org.joonzis.test;
public class Coordinate {
int x, y;
public Coordinate() {}
public Coordinate(int x, int y) {
this.x = x;
this.y = y;
}
void output() {
System.out.println("좌표 : [" + x + ", " + y + "]");
}
}
package org.joonzis.test;
public class CoordinateCircleRingMain {
public static void main(String[] args) {
Coordinate coo = new Coordinate(0, 0);
Circle cir1 = new Circle(coo, 10);
Circle cir2 = new Circle(coo, 12);
Ring ring = new Ring(cir1, cir2);
ring.output();
}
}
package org.joonzis.test;
//필드 - int kor, int eng, int mat, double average, char grade
//메소드 - Constructor, getAverage(평균을 리턴), getGrade(학점을 리턴)
// 학점 : 90이상 A, 80이상 B, 70이상 C, 60이상 D, 60미만 F
public class Grade {
int kor, eng, mat;
double average;
char grade;
public Grade() {
}
public Grade(int kor, int eng, int mat) {
this.kor = kor;
this.eng = eng;
this.mat = mat;
}
double getAverage() {
return (kor + eng + mat) / 3.0;
}
char getGrade() {
if (getAverage() >= 90) {
return 'A';
} else if (getAverage() >= 80) {
return 'B';
} else if (getAverage() >= 70) {
return 'C';
} else if (getAverage() >= 60) {
return 'D';
} else {
return 'F';
}
}
}
package org.joonzis.test;
public class Ring {
Circle inner, outer;
public Ring() {}
public Ring(Circle inner, Circle outer) {
this.inner = inner;
this.outer = outer;
}
void output() {
System.out.println("안쪽 원의 정보");
inner.output();
System.out.println("바깥쪽 원의 정보");
outer.output();
}
}
package org.joonzis.test;
public class Singer {
String name;
Song song;
public Singer() {}
public Singer(String name) {
this.name = name;
}
void setSong(Song s) {
this.song = s;
}
void output() {
System.out.println("가수 이름 : " + name);
song.output();
}
}
package org.joonzis.test;
public class SingerSongMain {
public static void main(String[] args) {
Song s = new Song("got you", "한국");
Singer singer = new Singer("신비아파트");
singer.setSong(s);
singer.output();
}
}
package org.joonzis.test;
//필드 - String title, String country
//메소드 - Constructor, output
public class Song {
String title, country;
public Song() {
}
public Song(String title, String country) {
this.title = title; // this(명령어) 구분해주는것
this.country = country;
}
void output() {
System.out.println("노래 제목 : " + title);
System.out.println("국가 : " + country);
}
}
package org.joonzis.test;
public class Student {
String name, dept;
Grade grade;
public Student() {}
public Student(String name, String dept, Grade grade) {
this.name = name;
this.dept = dept;
this.grade = grade;
}
void output() {
System.out.println("학생 이름 : " + name);
System.out.println("학생 학과 : " + dept);
System.out.println("평균 : " + grade.getAverage());
System.out.println("학점 : " + grade.getGrade());
}
}
package org.joonzis.test;
public class StudentGradeMain {
public static void main(String[] args) {
Grade g = new Grade(70,80,90);
Student stu = new Student("김씨","컴공", g);
stu.output();
}
}
