public ColorTV(int size, int color) {
super(size);
this.color = color;
}
import java.util.Scanner;
class A {
A(){
System.out.println("A class");
}
}
class B extends A{
B(){
System.out.println("B class");
}
}
class C extends B{
C(){
System.out.println("C class");
}
}
public class JavaTest {
public static void main(String[] args) {
new C();
}
}
[Console]
A class
B class
C class
class 동물 {}
class 사람 extends 동물 {}
class 소 extends 동물 {}
class 새 extends 동물 {}
class Computer{
Cpu cpu;
Memory memory;
}
class MobilePhone {
protected String number; // 전화번호
public MobilePhone(String num) {
number = num;
}
public void answer() {
System.out.println("Hi~ from " + number);
}
}
class SmartPhone extends MobilePhone {
private String androidVer; // 운영체제 버전
public SmartPhone(String num, String ver) {
super(num);
androidVer = ver;
}
public void playApp() {
System.out.println("App is running in " + androidVer);
}
}
public class JavaTest {
public static void main(String[] args) {
SmartPhone phone = new SmartPhone("010-555-7777", "Nougat");
phone.answer();
phone.playApp();
}
}
[Console]
Hi~ from 010-555-7777
App is running in Nougat
부모는 자식이 될 수 있지만, 자식은 부모가 될 수 없다
class A {
int a;
void printA() {
System.out.println("A");
}
}
class B extends A{
int b;
void printB() {
System.out.println("B");
}
}
public class JavaPractice {
public static void main(String[] args) {
A a = new A();
a.printA();
B b = new B();
b.printB();
b.printA();
A aa = new B();
aa.printA();
// B bb = new A();
}
}
class MobilePhone {
protected String number; // 전화번호
public MobilePhone(String num) {
number = num;
}
public void answer() {
System.out.println("Hi~ from " + number);
}
}
class SmartPhone extends MobilePhone {
private String androidVer; // 운영체제 버전
public SmartPhone(String num, String ver) {
super(num);
androidVer = ver;
}
public void playApp() {
System.out.println("App is running in " + androidVer);
}
}
public class JavaTest {
public static void main(String[] args) {
SmartPhone phone = new SmartPhone("010-555-7777", "Nougat");
MobilePhone phone2 = new SmartPhone("010-999-3333", "Nougat");
phone.answer();
phone.playApp();
System.out.println();
phone2.answer();
//phone2.playApp();
}
}
class Employee {
String name;
int age;
String address;
String position;
int salary;
public Employee(String name, int age, String address, String position) {
this.name = name;
this.age = age;
this.address = address;
this.position = position;
}
public void printInfo() {
System.out.println("이름 : " + name);
System.out.println("나이 : " + age);
System.out.println("주소 : " + address);
System.out.println("부서 : " + position);
}
}
class Regular extends Employee {
public Regular(String name, int age, String address, String position) {
super(name, age, address, position);
}
public void setSalary(int salary) {
super.salary = salary;
}
public void printInfo() {
super.printInfo();
System.out.println("정규직입니다");
System.out.println("월급 : " + super.salary);
}
}
public class JavaPractice {
public static void main(String[] args) {
Regular a = new Regular("김철수", 20, "인천", "대리");
a.setSalary(2000);
a.printInfo();
}
}
[Console]
이름 : 김철수
나이 : 20
주소 : 인천
부서 : 대리
정규직입니다
월급 : 2000