객체지향 연습문제(1)
package practice.account;
public class Account {
private String owner;
private int balance;
public Account(String owner, int balance) {
this.owner = owner;
this.balance = balance;
}
public void deposit(int amount) {
balance = balance + amount;
System.out.println(balance);
}
public void withdraw(int amount) {
if (balance >= amount) {
balance = balance - amount;
System.out.println(balance);
} else {
System.out.println("잔액이 부족합니다.");
}
}
public void showInfo() {
System.out.println("예금주: " + owner);
System.out.println("잔액: " + balance);
}
public static void main(String[] args) {
Account account = new Account("철수", 10000);
account.deposit(5000);
account.withdraw(3000);
account.withdraw(20000);
account.showInfo();
}
}객체지향 연습문제(2)
package practice.book2;
public class Book {
private String title;
private boolean borrowed;
public Book(String title) {
this.title = title;
this.borrowed = false;
}
public void borrow() {
if (borrowed == false) {
borrowed = true;
} else {
System.out.println("이미 대출 중입니다.");
}
}
public void returnBook() {
if (borrowed == true) {
borrowed = false;
} else {
System.out.println("대출된 책이 아닙니다.");
}
}
public void showInfo() {
System.out.println("제목: " + title);
if (borrowed) {
System.out.println("상태: 대출 중");
} else {
System.out.println("상태: 대출 가능");
}
}
public static void main(String[] args) {
Book book = new Book("자바의 정석");
book.showInfo();
book.borrow();
book.borrow();
book.showInfo();
book.returnBook();
book.showInfo();
}
}객체지향 연습문제(3)
package practice.book3;
public class Book {
private String title;
public Book(String title) {
this.title = title;
}
public String getTitle() {
return title;
}
}
class Student {
private String name;
private Book book;
public Student(String name) {
this.name = name;
}
public void borrowBook(Book book) {
this.book = book;
}
public void showInfo() {
System.out.println("학생이름: " + name);
if (book == null) {
System.out.println("빌린 책: 없음");
} else {
System.out.println("빌린 책: " +book.getTitle());
}
}
public static void main(String[] args) {
Book book1 = new Book("자바의 정석");
Student student = new Student("철수");
student.showInfo();
student.borrowBook(book1);
student.showInfo();
}
}객체지향 연습문제(4)
package practice.car;
public class Car {
private String model;
private boolean engineOn;
public Car(String model) {
this.model = model;
engineOn = false;
}
public void startEngine() {
if (engineOn == false) {
engineOn = true;
} else {
System.out.println("이미 시동이 켜져있습니다.");
}
}
public void stopEngine() {
if (engineOn == true) {
engineOn = false;
} else {
System.out.println("이미 시동이 꺼져있습니다.");
}
}
public boolean isRunning() {
return engineOn;
}
public void showInfo() {
System.out.println("모델: " + model);
if (engineOn == true) {
System.out.println("상태: 운행 중");
} else {
System.out.println("상태: 정지");
}
}
public static void main(String[] args) {
Car car = new Car("소나타");
car.showInfo();
car.startEngine();
System.out.println("운행 중인가? " + car.isRunning());
car.showInfo();
car.stopEngine();
car.showInfo();
}
}마무리
부족한 객체지향 연습문제를 꾸준히 풀고 있다.
AI 도움 없이 혼자서 풀려니까 확실히 시간이 오래걸리고 더디긴하지만 하나씩 풀어가는 날 보며 뿌듯함을 느꼈다.
얼른 실력이 무럭무럭 자랐으면 좋겠다!
