Chapter 6 객체지향 프로그래밍 1

자기개발/Java

Chapter 6 객체지향 프로그래밍 1

실버블렛 2012. 1. 21. 15:37

class BlockTest
{
static {
System.out.println("static{}");
}

{
System.out.println("{}");
}

public BlockTest(){
  System.out.println("생성자");
}
public static void main(String[] args)
{
  System.out.println("BlockTest bt = new BlockTest();");
  BlockTest bt = new BlockTest();

  System.out.println("BlockTest bt2 = new BlockTest();");
  BlockTest bt2 = new BlockTest();
}
}

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class CallStackTest
{
public static void main(String[] args)
{
  firstMethod();
}

static void firstMethod(){
secondMethod();
}

static void secondMethod(){
  System.out.println("secondMethod()");
}
}

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class CallStackTest2
{
public static void main(String[] args)
{
  System.out.println("main(String[] args) 이 시작되었음.");
  firstMethod();
  System.out.println("main(String[] args) 이 끝났음.");
}

static void firstMethod(){
  System.out.println("firstMethod() 이 시작되었음.");
  secondMethod();
  System.out.println("firstMethod() 이 끝났음.");
}

static void secondMethod(){
  System.out.println("secondMethod() 이 시작되었음.");
  System.out.println("secondMethod() 이 끝났음.");
}
}

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class CardTest
{
public static void main(String[] args)
{
  System.out.println("Card.width = " + Card.width);
  System.out.println("Card.height = " + Card.height);

  Card c1 = new Card();
  c1.kind = "Heart";
  c1.number = 7;

  Card c2 = new Card();
  c2.kind = "Space";
  c2.number = 4;

System.out.println("c1은 " + c1.kind + ", " + c1.number + "이며, 크기는 (" + c1.width + ", " + c1.height + ")" );
System.out.println("c2은 " + c2.kind + ", " + c2.number + "이며, 크기는 (" + c2.width + ", " + c2.height + ")" );

  c1.width = 50; //Card.width = 50;
  c1.height = 80; //Card.height = 80;
  System.out.println("c1의 width와 height를 각각 50,80으로 변경합니다.");

class Card
{
String kind;
int number;
static int width = 100;
static int height = 250;
}
----------------------------------------------------------------------------------------
class Car{
String color;
String gearType;
int door;

Car() {};
Car(String color, String gearType, int door) {
  this.color = color;
  this.gearType = gearType;
  this.door = door;
};
}

class CarTest
{
public static void main(String[] args)
{
  Car c1 = new Car();
  c1.color = "white";
  c1.gearType = "auto";
  c1.door = 4;

Car c2 = new Car("white", "auto", 4);

System.out.println("c1의 color=" + c1.color + "c1의 gearType=" + c1.gearType + "c1의 door=" + c1.door);
System.out.println("c2의 color=" + c2.color +"c2의 gearType=" + c2.gearType +"c2의 door=" + c2.door);
}
}

----------------------------------------------------------------------------------------
class Car{
String color;
String gearType;
int door;

Car() {
this("white", "auto", 4);
};

Car(String color) {
  this(color, "auto", 4);
};
Car(String color, String gearType, int door) {
  this.color = color;
  this.gearType = gearType;
  this.door = door;
};
}

class CarTest2
{
public static void main(String[] args)
{
Car c1 = new Car();
Car c2 = new Car("blue");

System.out.println("c1의 color=" + c1.color + ", c1의 gearType=" + c1.gearType + ", c1의 door=" + c1.door);
System.out.println("c2의 color=" + c2.color +", c2의 gearType=" + c2.gearType +", c2의 door=" + c2.door);
}
}

----------------------------------------------------------------------------------------
class Car{
String color;
String gearType;
int door;

Car() {
this("white", "auto", 4);
};

Car(Car c) {
  color=c.color;
     gearType=c.gearType;
     door=c.door;
};
Car(String color, String gearType, int door) {
  this.color = color;
  this.gearType = gearType;
  this.door = door;
};
}

class CarTest3
{
public static void main(String[] args)
{
Car c1 = new Car();
Car c2 = new Car(c1);

  c1.door = 100;
  System.out.println("c1.door = 100; 수행 후");
  System.out.println("c1의 color=" + c1.color + ", c1의 gearType=" + c1.gearType + ", c1의 door=" + c1.door);
  System.out.println("c2의 color=" + c2.color +", c2의 gearType=" + c2.gearType +", c2의 door=" + c2.door);
}
}

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class Date1 {
int value;
}

class Date2{
int value;

Date2(int x){
value = x;
}
}

class ConstructorTest
{
public static void main(String[] args)
{
  Date1 d1 = new Date1();
  Date2 d2 = new Date2(5);
  //Date2 d2 = new Date2(); //error
}
}

----------------------------------------------------------------------------------------
class Document{
static int count=0;
String name;

public Document() {
this("제목없음" + ++count);
//System.out.println("문서 제목없음" + ++count + "가 생성되었습니다.");
}

public Document(String name){
this.name = name;
System.out.println("문서 " + name + "가 생성되었습니다.");
}

}

class DocumentTest
{
public static void main(String[] args)
{
  Document d1 = new Document();
  Document d2 = new Document("자바.txt");
  Document d3 = new Document();
  Document d4 = new Document();
}
}

----------------------------------------------------------------------------------------
class FactorialTest
{
public static void main(String[] args)
{
  System.out.println(factorial(4));
}

static long factorial(int n){
long result = 0;

  if (n == 1) {
   result = 1;
  } else result = n * factorial(n-1);
  return result;
}
}

----------------------------------------------------------------------------------------
class MainTest
{
public static void main(String[] args)
{
  main(null); //자기 자신을 다시 호출한다.
}
}

----------------------------------------------------------------------------------------
class MyMathTest
{
public static void main(String[] args)
{
  MyMath mm = new MyMath();
  long result1 = mm.add( 5L, 3L);
  long result2 = mm.subtract( 5L, 3L);
  long result3 = mm.multiply( 5L, 3L);
  double result4 = mm.divide( 5L, 3L);

  System.out.println(result1);
  System.out.println(result2);
  System.out.println(result3);
  System.out.println(result4);
}
}

class MyMath{
long add(long a, long b){
return a + b; //int result = a + b; return result;
}
long subtract(long a, long b) { return a - b; }
long multiply(long a, long b){ return a * b; }
double divide(double a, double b){ return a / b; }
}
----------------------------------------------------------------------------------------
class MyMath2 {
long a, b;

long add(){ return a + b; }
long substract(){ return a - b; }
long multiply(){ return a * b; }
double divide(){ return a / b; }

static long add(long a, long b){ return a + b; }
static long substract(long a, long b){ return a - b; }
static long multiply(long a, long b){ return a * b; }
static double divide(double a, double b){ return a / b; }

}

class MyMathTest2
{
public static void main(String[] args)
{
  System.out.println(MyMath2.add(200L, 100L));
  System.out.println(MyMath2.substract(200L, 100L));
  System.out.println(MyMath2.multiply(200L, 100L));
  System.out.println(MyMath2.divide(200.0, 100.0));

  MyMath2 mm = new MyMath2();
  mm.a = 200L;
  mm.b = 100L;
  System.out.println(mm.add());
  System.out.println(mm.substract());
  System.out.println(mm.multiply());
  System.out.println(mm.divide());
}
}

----------------------------------------------------------------------------------------
class OverloadTest
{
public static void main(String[] args)
{
  MyMath3 mm = new MyMath3();
  System.out.println("mm.add(3, 3) 결과:" + mm.add(3, 3));
  System.out.println("mm.add(3L, 3) 결과:"+ mm.add(3L, 3));
  System.out.println("mm.add(3, 3L) 결과:"+ mm.add(3, 3L));
  System.out.println("mm.add(3L, 3L) 결과:"+ mm.add(3L, 3L));

int[] a = {100, 200, 300};
System.out.println("mm.add(a) 결과:" + mm.add(a));

}
}

class MyMath3{
int add(int a, int b){
System.out.print("int add(int a, int b) - ");
return a + b;
}

long add(long a, int b){
System.out.print("long add(long a, int b) - ");
return a + b;
}

long add(int a, long b){
System.out.print("long add(int a, long b) - ");
return a + b;
}

long add(long a, long b){
System.out.print("int add(long a, long b) - ");
return a + b;
}

int add(int[] a){
  System.out.print("int add(int[] a) - ");
  int result = 0;
  for(int i=0; i<a.length; i++){
   result += a[i];
  }
  return result;
}

}

----------------------------------------------------------------------------------------
class Data {
int x;
}

class ParameterTest
{
public static void main(String[] args)
{
  Data d = new Data();
  d.x = 10;
  System.out.println("main() : x = " + d.x);

  change(d.x);
  System.out.println("After change(d.x)");
  System.out.println("main() : x = " + d.x);
}
static void change(int x){
  x = 1000;
  System.out.println("change() : x = " + x);
}
}

----------------------------------------------------------------------------------------
class Data {
int x;
}

class ParameterTest2
{
public static void main(String[] args)
{
  Data d = new Data();
  d.x = 10;
  System.out.println("main() : x = " + d.x);

  change(d);
  System.out.println("After change(d.x)");
  System.out.println("main() : x = " + d.x);
}
static void change(Data d){
  d.x = 1000;
  System.out.println("change() : x = " + d.x);
}
}

----------------------------------------------------------------------------------------
class Data {
int x;
}

class ParameterTest3
{
public static void main(String[] args)
{
int[] x = {10};
System.out.println("main() : x = " + x[0]);

  change(x);
  System.out.println("After change(x)");
  System.out.println("main() : x = " + x[0]);
}
static void change(int[] x){
  x[0] = 1000;
  System.out.println("change() : x = " + x[0]);
}
}

----------------------------------------------------------------------------------------
class PowerTest
{
public static void main(String[] args)
{
  int x = 2;
  int n = 5;
  long result = 0;

  for (int i=1; i<=n; i++) {
  result += power( x, i);
  }
  System.out.println(result);
}

static long power(int x, int n){
  //return (n == 1) ? x : x * power(x, n-1);

  if (n == 1) {
   return x;
  } else { return x * power(x, n-1); }

}
}

----------------------------------------------------------------------------------------
class Product{
static int count = 0;
int serialNo;

{
count++;
serialNo = count;
}
}

class ProductTest
{
public static void main(String[] args)
{
  Product p1 = new Product();
  Product p2 = new Product();
  Product p3 = new Product();

  System.out.println("p1의 제품번호(serial no)는 " + p1.serialNo);
  System.out.println("p2의 제품번호(serial no)는 " + p2.serialNo);
  System.out.println("p3의 제품번호(serial no)는 " + p3.serialNo);
  System.out.println("생산된 제품의 수는 모두 " + Product.count + "개 입니다.");
}
}

----------------------------------------------------------------------------------------
class ReturnTest
{
public static void main(String[] args)
{
  ReturnTest r = new ReturnTest();

int result = r.add(3,5);
System.out.println(result);

  int[] result2 = {0};
  r.add(3,5,result2);
  System.out.println(result2[0]);
}

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

void add(int a, int b, int[] result){
result[0] = a+b;
}
}
----------------------------------------------------------------------------------------
class StaticBlockTest
{
static int[] arr = new int[10];

static {
  for (int i=0; i<arr.length; i++) {
   arr[i] = (int)(Math.random()*10)+1;
  }
}
public static void main(String[] args)
{
  for (int i=0; i<arr.length; i++) {
  System.out.println("arr[" + i + "] :" + arr[i]);
  }

}
}

----------------------------------------------------------------------------------------
class Tv{
// Tv의 속성 (맴버변수)
String color; // 색상
boolean power; // 전원상태(on/off)
int channel; //채널

// Tv의 기능 (메서드)
void power() { power = !power; }
void channelUp() { ++channel; }
void channelDown() { --channel; }
}

class TvTest
{
public static void main(String[] args)
{
  Tv t = new Tv(); // Tv 인스턴스를 참조하기 위한 참조변수 t선언 후 Tv 인스턴스 생성한다.
  t.channel = 7; // Tv 인스턴스의 멤버변수 channel의 값을 7로 한다.
  t.channelDown(); // Tv 인스턴스의 메서드 channelDown()을 호출한다.
  System.out.println("현재 채널은 " + t.channel + "입니다."); //
}
}

----------------------------------------------------------------------------------------
class Tv{
// Tv의 속성 (맴버변수)
String color; // 색상
boolean power; // 전원상태(on/off)
int channel; //채널

// Tv의 기능 (메서드)
void power() { power = !power; }
void channelUp() { ++channel; }
void channelDown() { --channel; }
}

class TvTest2
{
public static void main(String[] args)
{
  Tv t1 = new Tv();
  Tv t2 = new Tv();
  System.out.println("t1의 channel값은 " + t1.channel + "입니다.");
  System.out.println("t2의 channel값은 " + t2.channel + "입니다.");

t1.channel = 7;
System.out.println("t1의 channel값을 " + t1.channel + "로 변경하였습니다.");

System.out.println("t1의 channel값은 " + t1.channel + "입니다.");
System.out.println("t2의 channel값은 " + t2.channel + "입니다.");
}
}

----------------------------------------------------------------------------------------
class Tv{
// Tv의 속성 (맴버변수)
String color; // 색상
boolean power; // 전원상태(on/off)
int channel; //채널

// Tv의 기능 (메서드)
void power() { power = !power; }
void channelUp() { ++channel; }
void channelDown() { --channel; }
}

class TvTest3
{
public static void main(String[] args)
{
  Tv t1 = new Tv();
  Tv t2 = new Tv();
  System.out.println("t1의 channel값은 " + t1.channel + "입니다.");
  System.out.println("t2의 channel값은 " + t2.channel + "입니다.");

  t2 = t1;
  t1.channel = 7;
  System.out.println("t1의 channel값을 " + t1.channel + "로 변경하였습니다.");

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현재글Chapter 6 객체지향 프로그래밍 1

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