abc
package abc;
class Circle{
double r;
public Circle(double a) {
r=a;
}
public double getArea() {
return r * r * 3.14;
}
public double getRadius() {
return r;
}
}
public class aa {
public static void main(String[] args) {
Circle c = new Circle(5);
System.out.println(c.r);
System.out.println(c.getRadius());
System.out.println(c.getArea());
}
}package abc;
import java.util.*;
public class bb {
int width;
int height;
public int getArea() {
return width * height;
}
public static void main(String[] args) {
bb rect = new bb();
Scanner ad = new Scanner(System.in);
System.out.print(">>");
rect.width= ad.nextInt();
rect.height= ad.nextInt();
System.out.println("사각형의 면적은 "+ rect.getArea());
}
}package abc;
public class cc {
int radius;
String name;
public double getArea() {
return 3.14 * radius * radius;
}
public static void main(String[] args) {
cc pizza;
pizza = new cc();
pizza.radius = 10;
pizza.name = "피자";
double area = pizza.getArea();
System.out.println(pizza.name + "의 면적은 " + area);
cc dount = new cc();
dount.radius = 2;
dount.name = "도넛";
area = dount.getArea();
System.out.println(dount.name + "의 면적은 " + area);
}
}package abc;
public class dd {
int radius;
void set(int r) {
radius = r;
}
double getArea() {
return 3.14 * radius * radius;
}
public dd(int r) {
radius = r;
}
public static void main(String[] args) {
dd pizza = new dd(10);
System.out.println(pizza.getArea());
dd dount = new dd(2);
System.out.println(dount.getArea());
}
}package abc;
public class ee {
int radius;
String name;
public ee() {
radius = 1; name = "";
}
public ee(int r, String n) {
radius = r; name = n;
}
public double getArea() {
return 3.14 * radius * radius;
}
public static void main(String[] args) {
ee pizza = new ee(10, "피자");
double area = pizza.getArea();
System.out.println(pizza.name + "의 면적은 " + area);
ee dount = new ee();
dount.name = "도넛";
area = dount.getArea();
System.out.println(dount.name + "의 면적은 " + area);
}
}package abc;
class ff {
String title;
String author;
public ff(String t){
title = t;
author = "작자미상";
}
public ff(String t, String a) {
title = t;
author = a;
}
public static void main(String[] args) {
ff littlePrince = new ff("어린 왕자", "생텍쥐베리");
ff loveStory = new ff("춘향전");
System.out.println(littlePrince.title + " " + littlePrince.author);
System.out.println(loveStory.title + " " + loveStory.author);
}
}thread
package Thread;
class MyThread extends Thread{
@Override
public void run() {
for(int i = 0;i<10;i++)
System.out.println(getName());
}
}
public class Main10 {
public static void main(String[] args) {
//MyThread my_thread= new MyThread();
//my_thread.start();
Thread t1=new MyThread(); t1.start();
Thread t2=new MyThread(); t2.start();
System.out.println("main");
}
}package Thread;
class MyThread00 implements Runnable{
@Override
public void run() {
System.out.println("Thread"); }
}
public class Main11_01 {
public static void main(String[] args) {
Thread my_thread=new Thread(new MyThread00());
my_thread.start();
}
}package Thread;
class MyThread01 implements Runnable {
public void run() {
for(int i=0;i<10;i++)
System.out.println(Thread.currentThread().getName());
}
}
public class Main11 {
public static void main(String[] args) {
Thread t1=new Thread(new MyThread01(),"thd0"); t1.start();
Thread t2=new Thread(new MyThread01(),"thd1"); t2.start();
System.out.println("main");
}
}package Thread;
class MyThread09 implements Runnable {
public void run() {
for (int i = 0; i < 100; i++) {
String thd_name=Thread.currentThread().getName();
System.out.print(thd_name + " ");
if (thd_name.equals("thd1")) Thread.yield();
}
}
}
public class Main12 {
public static void main(String[] args) {
Thread my_thread1 = new Thread(new MyThread09(), "thd1");
Thread my_thread2 = new Thread(new MyThread09(), "thd2");
my_thread1.start();
my_thread2.start();
}
}package Thread;
class MyThread4 extends Thread{
public MyThread4(String szName) {
super(szName);
}
@Override
public void run() {
for(int i=0;i<100;i++) {
String num=String.valueOf(i);
if (i<10) num="0" + String.valueOf(i);
System.out.print(getName()+"("+num+")");
}
}
}
public class Main13 {
public static void main(String[] args) {
MyThread4 my_thread1=new MyThread4("thd1");
MyThread4 my_thread2=new MyThread4("thd2");
MyThread4 my_thread3=new MyThread4("thd3");
my_thread1.setPriority(Thread.MIN_PRIORITY);
my_thread2.setPriority(Thread.NORM_PRIORITY);
my_thread3.setPriority(Thread.MAX_PRIORITY);
my_thread1.start();
my_thread2.start();
my_thread3.start();
}
}package Thread;
class MyThread05 implements Runnable{
public void run() {
for(int i=0;i<100;i++) {
System.out.print((Thread.currentThread()).getName()+" ");
Thread.yield(); }
}
}
public class Main20 {
public static void main(String[] args) throws InterruptedException
{
Thread my_thread1=new Thread(new MyThread05(),"thd1");
Thread my_thread2=new Thread(new MyThread05(),"thd2");
my_thread1.start();
my_thread2.start();
my_thread1.join();
my_thread2.join();
System.out.println("main thread");
}
}package Thread;
class Counter{
private int c=0;
public synchronized void increment() { c++; }
public synchronized void decrement() { c--; }
public int value() { return c; }
}
/*
class Counter{
private int c=0;
public void increment() {synchronized (this) { c++;} }
public void decrement() {synchronized (this) {c--;} }
public int value() { return c; }
}
*/
class MyThread06 implements Runnable{
Counter c;
public MyThread06(Counter c) { this.c=c; }
public void run() {
for (int i=0;i<100000;i++)
c.increment(); } }
class MyThread07 implements Runnable{
Counter c;
public MyThread07 (Counter c) { this.c=c;
}
public void run() {
for (int i=0;i<100000;i++)
c.decrement();
} }
public class Main21 {
public static void main(String[] args) throws InterruptedException{
Counter c=new Counter();
Thread t1=new Thread(new MyThread06(c));
Thread t2=new Thread(new MyThread07(c));
t1.start();t2.start();
t1.join();t2.join();
System.out.println(c.value());
}
}