Learn AGGREGATION in 9 minutes! 🏫

#java #javatutorial #javacourse

public class Main {
public static void main(String[] args) {

// Aggregation = Represents a "has-a" relationship between objects.
// One object contains another object as part of its structure,
// but the contained object/s can exist independently.

Book book1 = new Book("The Fellow of the Ring", 423);
Book book2 = new Book("The Two Towers", 352);
Book book3 = new Book("The Return of the King", 416);

Book[] books = {book1, book2, book3};

Library library = new Library("NYC Public Library", 1897, books);

library.displayInfo();
}
}

public class Book {

String title;
int pages;

Book(String title, int pages){
this.title = title;
this.pages = pages;
}

String displayInfo(){
return this.title + " (" + this.pages + " pages)";
}
}

public class Library {

String name;
int year;
Book[] books;

Library(String name, int year, Book[] books){
this.name = name;
this.year = year;
this.books = books;
}

void displayInfo() {
System.out.println("The " + this.year + " " + this.name);
System.out.println("Books Available:");
for (Book book : books) {
System.out.println(book.displayInfo());
}
}
}