Week 6: Methods of OO Programming/12B. Count the Wizards [instanceof]

The program has again defined the class FairyTaleCharacter and its derived classes Wizard, Nephew, and Superhero.

Write a method:
public static int countWizards(ArrayList<FairyTaleCharacter> characters)
that takes a list of different fairy tale characters as a parameter 
and returns the number of wizards in the list as an integer.





import java.util.ArrayList;
import java.util.Collections;
import java.util.Random;

public class Test {
    public static void main(String[] args){
        final Random r = new Random();
        
        for (int test=1; test<=3; test++) {
            
            System.out.println("Test " + test);
            
            int age = r.nextInt(5) + 5;
            ArrayList<Integer> ages = new ArrayList<>();
            for (int i=0; i<20; i++) {
                ages.add(age);
                age += r.nextInt(10) + 1;
            }
            
            ArrayList<FairyTaleCharacter> characters = new ArrayList<>();
            String[] colors = "blue yellow red black brown white green".split(" ");
            
            for (String name : new String[] {"Benny", "Rupert", "Milo", "Charlie"}) {
                String color = colors[r.nextInt(colors.length)];
                characters.add(new Nephew(name, ages.remove(r.nextInt(ages.size())), color));
            }
            
            String[] superpowers = "super vision flight super strength reading ability super sneeze".split(" ");
            for (String name : new String[] {"Manbat", "Mouseman", "Bulk", "Copperman", "Steelcat"}) {
                String power = superpowers[r.nextInt(superpowers.length)];
                characters.add(new Superhero(name, ages.remove(r.nextInt(ages.size())), power));
            }
            
            ArrayList<FairyTaleCharacter> wizards = new ArrayList<>();
            String[] wands = "oak licorice birch alder walnut plastic".split(" ");
            for (String name : new String[] {"Harry", "Hermione", "Ron", "Voldemort", "Dumbledore", "Snape"}) {
                String wand = wands[r.nextInt(wands.length)];
                wizards.add(new Wizard(name, ages.remove(r.nextInt(ages.size())), wand));
            }
            
            int ch = r.nextInt(characters.size());
            int wz = r.nextInt(wizards.size());
            
            Collections.shuffle(characters, r);
            Collections.shuffle(wizards, r);
            
            ArrayList<FairyTaleCharacter> testList = new ArrayList<>();
            
            for (int i=0; i<ch; i++) {
                testList.add(characters.get(i));
            }
            
            for (int i=0; i<wz; i++) {
                testList.add(wizards.get(i));
            }
            
            Collections.shuffle(testList, r);
            
            System.out.println("Fairy Tale Characters:");
            testList.stream().forEach(c -> System.out.println("" + c));
            
            System.out.println("Wizards: " + countWizards(testList));
            
            System.out.println("");
        }
    }
    

    //ADD
    public static int countWizards(ArrayList<FairyTaleCharacter> characters) {
        int countWizards = 0;
        for (FairyTaleCharacter character : characters) {
            if (character instanceof Wizard) {
                countWizards++;
            }
        }
        return countWizards;
    }









}




class FairyTaleCharacter {
    private String name;
    private int age;
    
    public FairyTaleCharacter(String name, int age) {
        this.name = name;
        this.age = age;
    }
    
    public String getName() {
        return name;
    }
    
    public int getAge() {
        return age;
    }
    
    @Override
    public String toString() {
        return name + ", " + age + " years";
    }
}




class Nephew extends FairyTaleCharacter {
    private String capColor;

    public Nephew(String name, int age, String capColor) {
        super(name, age);
        this.capColor = capColor;
    }

    @Override
    public String toString() {
        return super.toString() + ", " + capColor + " cap (nephew)";
    }
}




class Wizard extends FairyTaleCharacter {
    private String wand;

    public Wizard(String name, int age, String wand) {
        super(name, age);
        this.wand = wand;
    }
    
    @Override
    public String toString() {
        return super.toString() + ", wand: " + wand + " (wizard)";
    }
}




class Superhero extends FairyTaleCharacter {
    private String superpower;

    public Superhero(String name, int age, String superpower) {
        super(name, age);
        this.superpower = superpower;
    }
    
    @Override
    public String toString() {
        return super.toString() + ", superpower: " + superpower + " (superhero)";
    }
}



















Test 1
Fairy Tale Characters:
Rupert, 111 years, white cap (nephew)
Milo, 69 years, blue cap (nephew)
Hermione, 105 years, wand: alder (wizard)
Steelcat, 42 years, superpower: flight (superhero)
Manbat, 98 years, superpower: super (superhero)
Snape, 50 years, wand: alder (wizard)
Wizards: 2

Test 2
Fairy Tale Characters:
Steelcat, 54 years, superpower: vision (superhero)
Manbat, 32 years, superpower: flight (superhero)
Hermione, 88 years, wand: birch (wizard)
Mouseman, 33 years, superpower: super (superhero)
Rupert, 53 years, green cap (nephew)
Wizards: 1

Test 3
Fairy Tale Characters:
Benny, 27 years, blue cap (nephew)
Copperman, 43 years, superpower: super (superhero)
Rupert, 140 years, green cap (nephew)
Steelcat, 108 years, superpower: super (superhero)
Mouseman, 120 years, superpower: flight (superhero)
Wizards: 0