Question

Write the following base class:

A friend on social media has the following features:

First Name

Last Name

Friendship level: values can be one of the choices best, ultra, great, good, acquaintance, the category was borrowed from PokemonGo

The friend has the following behaviors

Constructor/s: set MAX_IN_LEVEL as 2

toString: returns first, last names and friendship level as a String

improveFS: improve friendship level by one category higher

A friendGroup has the following features;

An arrayList of friends

The friendGroup has the following behaviors

Constructor/s: instantiate an ArrayList or assign value of friends to the instance variable

Display friends: use for each loop (enhanced for loop) to display all friends

findFriend(String first)

listFriends(friendship level passed as parameter): list all friends in that category

addFriend(Friend aFriend)

addFriend(int index, Friend aFriend)

removeFriend(String first)

removeAll(friendship level passed as parameter): remove all friends in that category

improvable(String first): check if the higher level of the friendship is full, if it is full, return false, if not, return true

improveFriend(String first): first check if the friendship can be improved, if it is improvable, improve the friendship

A tester class

               FriendGroup homies = new FriendGroup();

               homies.addFriend(new Friend("Tim", "Roberts", 4));

               homies.addFriend(new Friend("Mary", "Roberts", 4));

               homies.addFriend(new Friend("Tom", "Roberts", 3));

               homies.addFriend(new Friend("Tam", "Roberts", 2));

               homies.addFriend(3, new Friend("Terry", "Roberts", 3));                      homies.addFriend(new Friend("Carrie", "Roberts", 1));

;             

               homies.displayFriends();

               homies.listFriends(2);

               sysout(homies.improveFriend(“Terry”);

               homies.displayFriends();

               sysout(homies.improveFriend(“Carrie”);

               homies.listFriends(2);

               homies.removeFriend(“Mary”);

               homies.listFriends(4);

               sysout(homies.improveFriend(“Terry”);

               homies.removeAll(3);

               homies.displayFriends();

               sysout(findFriend(“Tam”);

Answer 1

Program:

Friend.java

 public class Friend{ /* Friend class to containing the details about a friend */ // Initializing the data members static final int MAX_IN_LEVEL = 2; public String firstName; public String lastName; public int friendshipLevel; // Storing possible values of friendship public String[] friendship = {"best", "ultra", "great", "good", "acquaintance"}; // Constructor to initialize a friend Friend(String firstName, String lastName, int friendshipLevel){ this.firstName = firstName; this.lastName = lastName; this.friendshipLevel = friendshipLevel; } // Method that return the string object of the class public String toString(){ return "First Name : " + this.firstName + "\nLast Name : " + this.lastName + "\nFriendship Level : " + friendship[this.friendshipLevel]; } // Method to improve friendship public void improveFS(){ // check whether the friendshipLevel is improvable if(this.friendshipLevel > 0){ this.friendshipLevel--; } } }

FriendGroup.java

 // importing Array List class import java.util.ArrayList; public class FriendGroup{ /* Class to organise a group of friends*/ // array list to store friends ArrayList<Friend> friends = new ArrayList<Friend>(); // Method to display details of all friends public void displayFriends(){ // Iterating over every object in arraylist for(Friend friend : this.friends){ System.out.println(friend.toString()); } } // Method to find whether a friend exists public boolean findFriend(String first){ // Iterating over every object in arraylist for(Friend friend : friends){ if(friend.firstName.equals(first)){ return true; } } return false; } // Method to list the friends of same level public void listFriends(int level){ // Iterating over every object in arraylist for(Friend friend : friends){ if(friend.friendshipLevel == level){ System.out.println(friend.toString()); } } } // Method to add a new friend to the list of friends public void addFriend(Friend aFriend){ this.friends.add(aFriend); } // Method to add a new friend to the list of friends with the index specified public void addFriend(int index, Friend aFriend){ this.friends.add(index, aFriend); } // Method to remove a friend from the list of friends public void removeFriend(String first){ // Iterating over every object in arraylist for(int i=0; i<friends.size(); i++){ if(friends.get(i).firstName.equals(first)){ friends.remove(i); } } } // Method to remove all friends that belong to the level specified public void removeAll(int level){ // Iterating over every object in arraylist for(int i=0; i<friends.size(); i++){ if(friends.get(i).friendshipLevel == level){ friends.remove(i); } } } // Method to verify whether friendship can be improvable public boolean improvable(String first){ // Iterating over every object in arraylist for(Friend friend : friends){ if(friend.firstName.equals(first)){ // check whether the friendshipLevel is best i.e 0 if(friend.friendshipLevel == 0){ return false; } } } return false; } // Method to improve friendship if it is improvable public boolean improveFriend(String first){ // Iterating over every object in arraylist for(Friend friend : friends){ if(friend.firstName.equals(first)){ // check whether the friendshipLevel is best i.e 0 if(friend.friendshipLevel != 0){ friend.improveFS(); return true; } } } return false; } }

TesterClass.java

 class TesterClass { public static void main(String[] args) { FriendGroup homies = new FriendGroup(); homies.addFriend(new Friend("Tim", "Roberts", 4)); homies.addFriend(new Friend("Mary", "Roberts", 4)); homies.addFriend(new Friend("Tom", "Roberts", 3)); homies.addFriend(new Friend("Tam", "Roberts", 2)); homies.addFriend(3, new Friend("Terry", "Roberts", 3)); homies.addFriend(new Friend("Carrie", "Roberts", 1)); homies.displayFriends(); homies.listFriends(2); System.out.println(homies.improveFriend("Terry")); homies.displayFriends(); System.out.println(homies.improveFriend("Carrie")); homies.listFriends(2); homies.listFriends(4); System.out.println(homies.improveFriend("Terry")); homies.removeAll(3); homies.removeFriend("Mary"); homies.displayFriends(); System.out.println(homies.findFriend("Tam")); } }

output:

First Name : Tim Last Name : Roberts Friendship Level : acquaintance First Name : Mary Last Name : Roberts Friendship Level : acquaintance First Name : Tom Last Name : Roberts Friendship Level : good First Name : Terry Last Name : Roberts Friendship Level : good First Name : Tam Last Name : Roberts Friendship Level : great First Name : Carrie Last Name : Roberts Friendship Level : ultra First Name : Tam Last Name : Roberts Friendship Level : great true First Name : Tim Last Name : Roberts Friendship Level : acquaintance First Name : Mary Last Name : Roberts Friendship Level : acquaintance First Name : Tom Last Name : Roberts Friendship Level : good First Name : Terry Last Name : Roberts Friendship Level : great First Name : Tam Last Name : Roberts Friendship Level : great First Name : Carrie Last Name : Roberts Friendship Level : ultra true First Name : Terry Last Name : Roberts Friendship Level : great First Name : Tam Last Name : Roberts Friendship Level : great First Name : Tim Last Name : Roberts Friendship Level : acquaintance First Name : Mary Last Name : Roberts Friendship Level : acquaintance true First Name : Tim Last Name : Roberts Friendship Level : acquaintance First Name : Terry Last Name : Roberts Friendship Level : ultra First Name : Tam Last Name : Roberts Friendship Level : great First Name : Carrie Last Name : Roberts Friendship Level : best true

Hope this helps!