java

//class book
public class Book{
protected String color;
protected int year;
Book(){color="";year=0;}
Book(String color, int year){
this.color=color;
this.year=year;
}
//seter
void setColor(String color){this.color=color;}
void setYear(int Year){this.Year=year;}
//geter
string getColor(){
return color;}
string getYear(){
return year;}
//function
public int numOfA(){
int count=0;
for(int i=0;iif(keimeno.charAt(i)=='a')
count ++;
}}
// klasi pou klironomi tin book
class EBook extends Book{
private String URL;

EBook(){super();URL="";}
EBook(string color,int year,string URL){
super(color year);
this.URL;
}//class ebook

public static void bublesort(Ebook onoma adikimenou[]){
for(int i=1;i for(int j=ebooks.length-1;j>=i;j--){
if (ebooks[j].getpages() EBook temp = new Ebook();
temp=ebooks[j];
ebooks[j]=ebooks[j-1];
ebooks[j-1]=temp;
}}}

public static void main(String[] args){
EBook[] ebooks = new EBook[5];//pinakas 5 vivliwn
for(int i=0;i ebooks[i]=new Ebook(/*"red",2000,"http"*/);}//epidi einai pinakas

ebooks[0].setPages (100);ebooks[1].setpages(210);//an valw adia orismata ta gemizw
for(int i=0;i<5;i++){
system.out.println();
system.out.println(ebooks[i].getPages());}