abstract class Employee{
  public abstract double earnings();
}
class YearWorker extends Employee{
  public double earnings(){
    return 200000;    
  }
}
class MonthWorker extends Employee{
  public double earnings(){
    return 10000;    
  }
}
class WeekWorker extends Employee{
  public double earnings(){
    return 5000;    
  }
}
class Company{
  Employee[] employee;
  double salaries=0;
  Company(Employee[] employee){
    this.employee=employee;
  }
  public double salariesPay(){
    salaries=0;
    for(int i=0;i<employee.length;i++){
      salaries+=employee[i].earnings();
    }
    return salaries;
  }
}

public class HardWork {
  public static void main(String[] args) {
    Employee[] employee=new Employee[20];
    for(int i=0;i<employee.length;i++){
      if(i%3==0)
        employee[i]=new WeekWorker();
      else if(i%3==1)
        employee[i]=new MonthWorker();
      else if(i%3==2)
        employee[i]=new YearWorker();
    }
    Company company=new Company(employee);
    System.out.println("公司年工资总额："+company.salariesPay());
  }
}

class People{
  protected double weight,height;
  public void speakHello(){
    System.out.println("yayawawa");
  }
  public void averageHeight(){
    height=173;
    System.out.println("Average Height:"+height);
  }
  public void averageWeight(){
    weight=70;
    System.out.println("Average Weight:"+weight);
  }
}
class ChinaPeople extends People{
  public void speakHello(){
    System.out.println("你好，吃了吗");
  }  
  public void averageHeight(){
    height=173;
    System.out.println("中国人的平均身高:"+height+"厘米");
  }
  public void averageWeight(){
    weight=67.34;
    System.out.println("中国人的平均体重:"+weight+"公斤");
  }
  public void chinaGongfu(){
    System.out.println("坐如钟，站如松，睡如弓");
  }
}
class AmericanPeople extends People{
  public void speakHello(){
    System.out.println("How do you do");
  }
  public void averageHeight(){
    height=188;
    System.out.println("American Average Height:"+height+"cm");
  }
  public void averageWeight(){
    weight=80.23;
    System.out.println("American Average Weight:"+weight+"kg");
  }
  public void americanBoxing(){
    System.out.println("直拳，勾拳");
  }
}
class BeijingPeople extends ChinaPeople{
  public void speakHello(){
    System.out.println("您好");
  }  
  public void averageHeight(){
    height=16;
    System.out.println("北京人的平均身高:"+height+"厘米");
  }
  public void averageWeight(){
    weight=6;
    System.out.println("北京人的平均体重:"+weight+"公斤");
  }
  public void beijingOpera(){
    System.out.println("京剧术语");
  }
}
public class Example {  
  public static void main(String[] args) {
    ChinaPeople chinaPeople=new ChinaPeople();
    AmericanPeople americanPeople=new AmericanPeople();
    BeijingPeople beijingPeople=new BeijingPeople();
    chinaPeople.speakHello();
    americanPeople.speakHello();
    beijingPeople.speakHello();
    chinaPeople.averageHeight();
    americanPeople.averageHeight();
    beijingPeople.averageHeight();
    chinaPeople.averageWeight();
    americanPeople.averageWeight();
    beijingPeople.averageWeight();
    chinaPeople.chinaGongfu();
    americanPeople.americanBoxing();
    beijingPeople.beijingOpera();
    beijingPeople.chinaGongfu();
  }
  
}

class A{
  int a,b;
  A(int a,int b){
    this.a=a;
    this.b=b;
    
  }
  public int f(int a, int b){
      int i,j,n=0;
      
      if (a<b)
          j=a;
      else
          j=b;
      for (i=1;i<=j;i++)
        if (a%i==0&&b%i==0)
             n = i;
      return n;
  }
}
class B extends A{
  B(int a, int b) {
    super(a, b);
  }
  A gys=new A(a,b);
  int m=gys.f(a,b);
  public int f(int a,int b){
    return a*b/m;
  }  
}

public class Test {
  public static void main(String[] args) {
    int a=45,b=30;
    A gys=new A(a,b);
    B gbs=new B(a,b);
    System.out.println(a+","+b+"的最大公约数为"+gys.f(a,b));
    System.out.println(a+","+b+"的最小公倍数为"+gbs.f(a,b));
  }

}

import java.lang.reflect.*;
class A{
  int x;
  float y;
  double z;
  A(){
    x=12;
    y=12.901f;
    z=0.123456;
  }
  A(int x,float y,double z){
    this.x=x;
    this.y=y;
    this.z=z;
  }
  public double getSum(){
    return x+y+z;
  }
  public void setX(int x){
    this.x=x;
  }
  public void setY(float y){
    this.y=y;
  }
  public void setZ(double z){
    this.z=z;
  }
}

public class ExampleOne {

  public static void main(String[] args) {
    A a=new A(12,34.9f,0.54321);
    Class cs=a.getClass();
    String className=cs.getName();
    Constructor[] con=cs.getDeclaredConstructors();
    Field[] field=cs.getDeclaredFields();
    Method[] method=cs.getDeclaredMethods();
    System.out.println("类的名字："+className);
    System.out.println("类中有如下的成员变量：");
    for(int i=0;i<field.length;i++)
      System.out.println(field[i].toString());
    System.out.println("类中有如下的方法：");
    for(int i=0;i<method.length;i++)
      System.out.println(method[i].toString());
    System.out.println("类中有如下的构造方法：");
    for(int i=0;i<con.length;i++)
      System.out.println(con[i].toString());
    
  }

}

class Rect{
  private double width,height,area;
  public double getArea(){
    area=width*height;
    return area;
  }
  public void setWidth(double x){
    width=x;
  }
  public void setHeight(double y){
    height=y;
  }
}
class Circle{
  private double radius,area;
  public double getArea(){
    area=Math.PI*radius*radius;
    return area;
  }
  public void setRedius(double r){
    radius=r;
  }
}
public class ExampleTwo {
  public static void main(String[] args) {
    try{
      Class cs=Class.forName("Rect");
      Rect rect=(Rect)cs.newInstance();
      rect.setWidth(100);
      rect.setHeight(10);
      System.out.println("rect的面积"+rect.getArea());
      cs=Class.forName("Circle");
      Circle circle=(Circle)cs.newInstance();
      circle.setRedius(100);
      System.out.println("circle的面积"+circle.getArea());
      cs=Class.forName("java.util.Date");
      java.util.Date date=(java.util.Date)cs.newInstance();
      System.out.println("现在的时间："+date.toString());
    }
    catch(Exception e){}
  }
}

import tom.jiafei.Trangle;
import java.util.Date;
class SunRise {
  public static void main(String[] args) {
    Trangle trangle=new Trangle(12,3,104);
    trangle.computeArea();
    trangle.modifyThreeSide(3,4,5);
    trangle.computeArea();
    Date date=new Date();
    System.out.println(date);    
  }

}

public class A {
  int a,b;
  A(int a,int b){
    this.a=a;
    this.b=b;
    
  }
  int GYS(int a, int b)
  {
      int i,j,n=0;
      
      if (a<b)
          j=a;
      else
          j=b;
      for (i=1;i<=j;i++)
      {
          if (a%i==0&&b%i==0)
             n = i;
      }
      return n;
  }
}

public class B {
  int a,b;
  A gys;
  B(int a,int b){
    this.a=a;
    this.b=b;
    this.gys=new A(a,b);
  }
  int GBS(int a,int b){
    return a*b/gys.GYS(a,b);
  }

}

class A {
  float a;
  static float b;
  void setA(float a){
    this.a=a;
  }
  void setB(float b){
    A.b=b;
  }
  float getA(){
    return a;
  }
  float getB(){
    return b;
  }
  void inputA(){
    System.out.println(a);
  }
  static void inputB(){
    System.out.println(b);
  }
}
public class Ex4_2 {
  public static void main(String[] args) {
    A.b=100;
    A.inputB();
    A cat=new A();
    A dog=new A();
    cat.setA(200);
    cat.setB(400);
    dog.setA(200);
    dog.setB(900);
    cat.inputA();
    cat.inputB();
    dog.inputA();
    dog.inputB();
  }

}

public class Sum_p78_1 {
  int a,count,d;
  Sum_p78_1(int a,int count,int d){
    this.a=a;
    this.count=count;
    this.d=d;
  }
  int sum(){
    return (2*a+(count-1)*d)*count/2;
  }
}

public class LetterList_p78_2 {
  LetterList_p78_2(){};
  void printLetterList(){
    char c='a';
    for(int i=(int)c;i<c+26;i++){
      System.out.print((char)i+" ");
    }
  }
}

public class Sum_p78_1 {
  int a,count,d;
  Sum_p78_1(int a,int count,int d){
    this.a=a;
    this.count=count;
    this.d=d;
  }
  int sum(){
    return (2*a+(count-1)*d)*count/2;
  }
}

public class Rational {
  int numerator,denominator;
  Rational(){}
  Rational(int a,int b){
    setNumeratorAndDenominator(a,b);
  }
  void setNumeratorAndDenominator(int a,int b){
    int c=f(Math.abs(a),Math.abs(b));
    numerator=a/c;
    denominator=b/c;
    if(numerator<0&&denominator<0){
      numerator=-numerator;
      denominator=-denominator;
    }
  }
  int getNumerator(){
    return numerator;
  }
  int getDenominator(){
    return denominator;
  }
  int f(int a,int b){
    if(a<b){
      int c=a;
      a=b;
      b=c;
    }
    int r=a%b;
    while(r!=0){
      a=b;
      b=r;
      r=a%b;
    }
    return b;
  }
  Rational add(Rational r){
    int a=r.getNumerator();
    int b=r.getDenominator();
    int newNumerator=numerator*b+denominator*a;
    int newDenominator=denominator*b;
    Rational result=new Rational(newNumerator,newDenominator);
    return result;
  }
  Rational sub(Rational r){
    int a=r.getNumerator();
    int b=r.getDenominator();
    int newNumerator=numerator*b-denominator*a;
    int newDenominator=denominator*b;
    Rational result=new Rational(newNumerator,newDenominator);
    return result;
  }
  Rational muti(Rational r){
    int a=r.getNumerator();
    int b=r.getDenominator();
    int newNumerator=numerator*a;
    int newDenominator=denominator*b;
    Rational result=new Rational(newNumerator,newDenominator);
    return result;
  }
  Rational div(Rational r){
    int a=r.getNumerator();
    int b=r.getDenominator();
    int newNumerator=numerator*b;
    int newDenominator=denominator*a;
    Rational result=new Rational(newNumerator,newDenominator);
    return result;
  }
}

public class Computer {
  public static void main(String[] args) {
    Rational r1;
    r1=new Rational(1,5);
    Rational r2;
    r2=new Rational(3,2);
    Rational result=r1.add(r2);
    int a=result.getNumerator();
    int b=result.getDenominator();
    double p=a;
    double q=b;
    double doubleResult=p/q;
    System.out.print("分数"+r1.getNumerator()+"/"+r1.getDenominator());
    System.out.print("与分数"+r2.getNumerator()+"/"+r2.getDenominator()+"的和等于");
    System.out.println(a+"/"+b+"="+doubleResult);
    r1.setNumeratorAndDenominator(4,7);
    r2.setNumeratorAndDenominator(-5,20);
    result=r1.muti(r2);
    a=result.getNumerator();
    b=result.getDenominator();
    p=a;
    q=b;
    doubleResult=p/q;
    System.out.print("分数"+r1.getNumerator()+"/"+r1.getDenominator());
    System.out.print("与分数"+r2.getNumerator()+"/"+r2.getDenominator()+"的积等于");
    System.out.println(a+"/"+b+"="+doubleResult);
  }

}

public class DectoBin {
  static int[] dectobin(int y){
    int[] res=new int[32];
    int i=-1;
    if(y>0)
      while(y>0){
        i++;
        res[i]=y%2;
        y/=2;
      }
    else
      System.exit(1);
    return res;
  }
  
  public static void main(String[] args) {
    int x,y;
    x=1234;
    y=5678;
    long result=0L;
    int[] b=new int[32];
    b=DectoBin.dectobin(y);
    for(int i=0;i<32;i++){
      if(b[i]==1)
        result+=x<<i;
    }
    System.out.print(x+"*"+y+"="+result);
  }

}

public class Fraction{
  private  int nume;   // 分子
  private  int deno;   // 分母
  
//  无参构造方法
  public Fraction(){
//    初始化实例变量
  }
  
//  有参构造方法
  public Fraction( int n,  int d ){
//    初始化实例变量
    nume=n;
    deno=d;
  }
  
//  化简分数方法
  void FracSimp(int n,  int d)
  {
//    求分数的分子和分母的最大公约数
    int c=f(Math.abs(n),Math.abs(d));
//    化简分数
    nume=n/c;
    deno=d/c;
    if(nume<0&&deno<0){
      nume=-nume;
      deno=-deno;
    }
  }
  int f(int a,int b){
    if(a<b){
      int c=a;
      a=b;
      b=c;
    }
    int r=a%b;
    while(r!=0){
      a=b;
      b=r;
      r=a%b;
    }
    return b;
  }
  
//  分数输出方法
  void FracOutput(){
//    输出分数的分子和分母
    System.out.print("分子："+nume+" 分母："+deno);
  }
  public static void main(String args[]){
//    定义第1个Fraction类的对象引用f1,调用无参构造方法
    Fraction f1=new Fraction();
//    定义第2个Fraction类的对象引用f2，调用有参构造方法
    Fraction f2=new Fraction(1,5);
//    调用化简分数方法
    f2.FracSimp(f2.nume,f2.deno);
//    调用分数输出方法
    f2.FracOutput();
  }
}

import java.text.*;

public class Product {
  private String name;
  
  private double price;
  
  private static DecimalFormat money = new DecimalFormat("$0.00");
  
  public Product() {
    name = " ";
    price = 0.00;
  }
  
  public String toProductString() {
    return name + " costs " + money.format(price);
  }
  public Product(String n, double p)
  {
    name=n;
    price=p;
  }

}// end class Product

public class Rectangel{
//实例变量的声明
  double length,width;
//构造方法的定义
  public Rectangel(){}
  public Rectangel(double l,double w){
    length=l;
    width=w;
  }
//perimeter方法定义
  double perimeter(){
    return (length+width)*2;
  }
//area方法定义
  double area(){
    return length*width;
  }
  public static void main(String []args){
//定义Rectangle类的对象引用r
    Rectangel r=new Rectangel(2,3);
//调用perimeter方法，并显示周长
    System.out.print("周长："+r.perimeter());
//调用area方法，并显示面积
    System.out.print(" 面积："+r.area());
  }
}

public class School{
    public static void main(String [] args){
      //创建新学生对象
      int[] s1_score={60,70,80,90,88,77};
      int[] s2_score={66,77,89,98,76,92};
      Student s1=new Student("30901111","0706","小刚","男",20,s1_score);
      Student s2=new Student("30902222","0708","小红","女",17,s2_score);
      //输出学生的基本信息
      System.out.print("学号："+s1.getSnum()+" 班级号："+s1.getCnum()+" 姓名："+s1.getSname()+" 分数："+
          s1.getSscore()[0]+" "+s1.getSscore()[1]+" "+s1.getSscore()[2]+" "+s1.getSscore()[3]+" "+
          s1.getSscore()[4]+" "+s1.getSscore()[5]);
      System.out.print("\n");
      System.out.print("学号："+s2.getSnum()+" 班级号："+s2.getCnum()+" 姓名："+s2.getSname()+" 分数："+
          s2.getSscore()[0]+" "+s2.getSscore()[1]+" "+s2.getSscore()[2]+" "+s2.getSscore()[3]+" "+
          s2.getSscore()[4]+" "+s2.getSscore()[5]);
      System.out.print("\n");
      System.out.print("学生数："+Student.getScount());
      //测试类变量值的变化
      s1.changeCnum("0707");
      s1.changeSage(22);
      s2.changeCnum("0709");
      s2.changeSage(23);
      System.out.print("\n");
      System.out.print("学号："+s1.getSnum()+" 班级号："+s1.getCnum()+" 姓名："+s1.getSname()+" 分数："+
          s1.getSscore()[0]+" "+s1.getSscore()[1]+" "+s1.getSscore()[2]+" "+s1.getSscore()[3]+" "+
          s1.getSscore()[4]+" "+s1.getSscore()[5]);
      System.out.print("\n");
      System.out.print("学号："+s2.getSnum()+" 班级号："+s2.getCnum()+" 姓名："+s2.getSname()+" 分数："+
          s2.getSscore()[0]+" "+s2.getSscore()[1]+" "+s2.getSscore()[2]+" "+s2.getSscore()[3]+" "+
          s2.getSscore()[4]+" "+s2.getSscore()[5]);
      System.out.print("\n");
      System.out.print("学生数："+Student.getScount());
    }
}

public class Student{
//设计一个类变量记录学生人数
  static int count;
//设计基本属性有“学号”、“班号”、“姓名”、“性别”、“年龄”、“成绩”（用数组表示6门课的成绩）
  private String Snum;
  private String Cnum;
  private String Sname;
  private String Ssex;
  private int Sage;
  private int Sscore[]=new int[6];

//设计构造方法，传递学生的个人信息
  public Student(String Sn,String Cn,String name,String sex,int age,int score[]){
    Snum=Sn;
    Cnum=Cn;
    Sname=name;
    Ssex=sex;
    Sage=age;
    Sscore=score;
    count++;
  }
//设计方法“获得学号”、“获得班号”、“获得姓名”、“获得成绩”
  String getSnum(){
    return Snum;
  }
  String getCnum(){
    return Cnum;
  }
  String getSname(){
    return Sname;
  }
  int[] getSscore(){
    return Sscore;
  }
//设计方法“修改年龄”、“修改班号”
  void changeSage(int newSage){
    Sage=newSage;
  }
  void changeCnum(String newCnum){
    Cnum=newCnum;
  }

//设计类方法“获得学生人数”
  static int getScount(){
    return count;
  }
}

import java.text.DecimalFormat;

public class Time {
  private int hour;
  
  private int minute;
  
  private int second;
  
  Time() {
    hour = 0;
    minute = 0;
    second = 0;
  }
  
  Time(int h) {
    hour = h;
    minute = 0;
    second = 0;
  }
  
  Time(int h, int m) {
    hour = h;
    minute = m;
    second = 0;
  }
  
  Time(int h, int m, int s) {
    hour = h;
    minute = m;
    second = s;
  }
  
  Time(Time time) {
    this.hour = time.getHour();
    this.minute = time.getMinute();
    this.second = time.getSecond();
  }
  
  public int getHour() {
    return hour;
  }
  
  public int getMinute() {
    return minute;
  }
  
  public int getSecond() {
    return second;
  }
  
  public String toUniversalString() {
    DecimalFormat twoDigits = new DecimalFormat("00");
    return twoDigits.format(getHour()) + ":"
    + twoDigits.format(getMinute()) + ":"
    + twoDigits.format(getSecond());
  }
  
  public String toStandardString() {
    DecimalFormat twoDigits = new DecimalFormat("00");
    return ((getHour() == 12 || getHour() == 0) ? 12 : getHour() % 12)
    + ":" + twoDigits.format(getMinute()) + ":"
    + twoDigits.format(getSecond())
    + (getHour() < 12 ? "AM" : "PM");
  }
}

import java.util.*;
public class GuessNumber {
  public static void main(String[] args) {
    System.out.println("给你一个1至100之间的整数，请猜测这个数");
    int realNumber=(int)(Math.random()*100)+1;
    int yourGuess=0;
    Scanner reader= new Scanner(System.in);
    System.out.println("请输入您的猜测：");
    if(reader.hasNextInt())
      yourGuess=reader.nextInt();
    while(yourGuess != realNumber){
      if(yourGuess > realNumber){
        System.out.println("猜大了，请再猜：");
        if(reader.hasNextInt())
          yourGuess=reader.nextInt();
      }
      else if(yourGuess < realNumber){
        System.out.println("猜小了，请再猜：");
        if(reader.hasNextInt())
          yourGuess=reader.nextInt();
      }
    }
    System.out.println("猜对了！");
  }

}

import java.util.*;
public class Number {
  public static void main(String[] args) {
    int number=0,d5,d4,d3,d2,d1;
    Scanner reader=new Scanner(System.in);
    System.out.println("从键盘输入一个1至99999之间的数");
    while(reader.hasNextInt()){
      number=reader.nextInt();
      if(number>=1 & number<=99999){
        d5=number/10000;
        d4=number%10000/1000;
        d3=number%1000/100;
        d2=number%100/10;
        d1=number%10;
        if(d5 != 0){
          System.out.printf("\n%d是5位数",number);
          if(d5==d1 & d4==d2)
            System.out.printf("\t%d是回文数",number);
          else
            System.out.printf("\t%d不是回文数",number);
        }
        else if(d4 != 0){
          System.out.printf("\n%d是4位数",number);
          if(d4==d1 & d3==d2)
            System.out.printf("\t%d是回文数",number);
          else
            System.out.printf("\t%d不是回文数",number);
        }
        else if(d3 != 0){
          System.out.printf("\n%d是3位数",number);
          if(d3==d1)
            System.out.printf("\t%d是回文数",number);
          else
            System.out.printf("\t%d不是回文数",number);
        }
        else if(d2 != 0){
          System.out.printf("\n%d是2位数",number);
          if(d1==d2)
            System.out.printf("\t%d是回文数",number);
          else
            System.out.printf("\t%d不是回文数",number);
        }
        else if(d1 != 0){
          System.out.printf("\n%d是1位数",number);
          System.out.printf("\n%d是回文数",number);
        }
      }
      else
        System.out.printf("\n%d不在1至99999之间",number);
      System.out.printf("%n可继续输入整数，或输入非整数结束程序%n");
    }
    System.out.printf("你输入的数据不是整数");
  }

}

import java.util.*;
public class SortFind {
  public static void main(String[] args) {
    int n=0,start,end,middle;
    System.out.println("从键盘输入一个整数，程序将判断该数是否在一个数组中");
    int a[]={12,34,9,-23,45,6,45,90,123,19,34};
    Arrays.sort(a);
    Scanner reader=new Scanner(System.in);
    while(reader.hasNextInt()){
      n=reader.nextInt();
      start=0;
      end=a.length;
      middle=(start+end)/2;
      int count=0;
      while(n!=a[middle]){
        if(n>a[middle])
          start=middle;
        else if(n<a[middle])
          end=middle;
        middle=(start+end)/2;
        count++;
        if(count>a.length/2)
          break;
      }
      if(count>a.length/2)
        System.out.println("："+n+"不在数组中");
      else
        System.out.println("："+n+"是数组中的元素");
      System.out.printf("%n可继续输入整数，或输入非整数结束程序%n");
    }
    System.out.println("你输入的数据不是整数");

  }

}

import java.util.*;
public class InputXOutY { //从键盘输入一个x值，程序输出y的值
  public static void main(String[] args) {
    double x,y;
    Scanner reader=new Scanner(System.in);
    System.out.printf("input x: \n");
    while(reader.hasNextDouble()){
      x=reader.nextDouble();
      if(x<0)
        y=-1+2*x;
      else if(x==0)
        y=-1;
      else
        y=-1+3*x;
      System.out.printf("y= %f\n",y);
    }

  }

}

import java.util.*;
public class SumOfNumsCanBeDBy3and7 {
  public static void main(String[] args) {
    int i=1,s=0;
    while(i<=1000){
      if(i%3==0 & i%7==0)
        s=s+i;        
      i++;
    }
    System.out.printf("sum= %d\n",s);

  }

}

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    ListBox1: TListBox;
    ListBox2: TListBox;
    Button1: TButton;
    procedure ListBox1DblClick(Sender: TObject);
    procedure ListBox2DblClick(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.ListBox1DblClick(Sender: TObject);
begin
  self.ListBox2.Items.Add(self.ListBox1.Items[self.ListBox1.ItemIndex]);
  self.ListBox1.Items.Delete(self.ListBox1.ItemIndex);
end;

procedure TForm1.ListBox2DblClick(Sender: TObject);
begin
  self.ListBox1.Items.Add(self.ListBox2.Items[self.ListBox2.ItemIndex]);
  self.ListBox2.Items.Delete(self.ListBox2.ItemIndex);
end;

procedure TForm1.Button1Click(Sender: TObject);
begin          
  showmessage(self.ListBox1.Items[self.ListBox1.ItemIndex]);
end;

end.

public class Hello {

  /**
   * @param args
   */
  public static void main(String[] args) {
    // TODO 自动生成方法存根
    System.out.println("你好，很高兴学习Java");
    A a=new A();
    a.fA();
  }
}
class A{
  void fA(){
    System.out.println("We are students");
  }
}

import java.applet.*;
import java.awt.*;
public class FirstApplet extends Applet{
  public void paint(Graphics g){
    g.setColor(Color.blue);
    g.drawString("这是一个Java Applet程序",12,30);
    g.setColor(Color.red);
    g.setFont(new Font("宋体",Font.BOLD,36));
    g.drawString("我改变了字体",12,70);
  }
}