java2实用教程(第2版)程序代码

}
}
public class Example4_20 extends Apple()
{yuan=new Circle();
}
public void paint(Graphics g)
{("yuan= "+,5,20);...");
}
}
class猫extends动物
}
public class Example4_17 extends Applet
{Son boy;
public void init()
{boy=new Son();
=; =120f;
="一个头"; ="两只手";
="两只脚";
}
public void paint(Graphics g)
{("我是儿子"),5,20);
{Trangle trangle=new Trangle(12,3,1);
trangle.计算面积();
trangle.修改三边(3,4,5);
trangle.计算面积();
}
}
例子
class Example4_16
{private int money;
Example4_16()
{money=2000;
例子
class Fibi
{ public long fibinacii(int n)
{ long c=0;
if(n==1||n==2)
c=1;
else
c=fibinacii(n-1)+fibinacii(n-2);
return c;
}
}
public class Example4_9
{ public static void main(String args[])
{ public static void main(String args[])
{ int sum=0,i,j;
for( i=1;i<=10;i++);
public class Example4_12 extends Applet
{ Button redbutton;
public void init()
{ =a;
=b;
=c;
}
}
class Example4_10
{ public static void main(String args[])
{三角形tra=new三角形(3,4,5);
"三角形型的三边是:"++","++","++",");
}
}
例子
package ;
public class PrimNumber
{void cry()
{"喵喵.....");
}
}
class Example4_22
{public static void main(String args[])
{动物dongwu;
import .*;
class Father
{private int money;
float weight,height;
String head;
String speak(String s)
{return s ;
}
}
class Son extends Father
{String hand ,foot;
{ Fibi a=new Fibi();
for(int i=1;i<=10;i++)
{ " "+(i));
}
}
}
例子
class三角形
{ double a,b,c;
三角形(double a,double b,double c)
{ setABC(this,a,b,c);
}
void setABC(三角形trangle,double a,double b,double c)
{ redbutton=new Button("我是一个红色的按钮");
;
add(redbutton);
}
public void paint(Graphics g)
{ ("it isabutton",30,50);
}
}
例子
import .*;;
class Example4_15
{public static void main(String args[])
{return x+y ;
}
}
public class Example4_19 extends Applet
{Xiangjia sum;
public void init()
{sum=new Xiangjia();
}
public void paint(Graphics g)
{("sum="+(4,6),100,40);
++++,5,40);
}
}
例子
:
package ;
public class Father
{int height;
protected int money;
public int weight;
public Father(int m) {
{money=m;
}
protected int getMoney()
}
private int getMoney()
{return money;
}
public static void main(String args[])
{Example4_16 exa=new Example4_16();
=3000;int m=();
"money="+m);
}
}
例子
import .*;
{return money;
}
void setMoney(int newMoney)
{money=newMoney;
}
}
:
package ;
import class Jerry extends Father{public Jerry()
{super(20);
}
public static void main(String args[])
{Jerry jerry=new Jerry();
=12;(300);;
import .*;
class Chengji
{float f(float x,float y)
{return x*y;
}
}
class Xiangjia extends Chengji
{float f(float x,float y)
}
}
例子
import .*;
import .*;
class Area
{float f(float r )
{return *r*r;
}
float g(float x,float y)
{return x+y;
}
}
class Circle extends Area
{float f(float r)
{return **r;