abstract class example has been added to the repo

src/Main.java

@@ -1,12 +1,46 @@
+import animal.type.app.Animal;
+import animal.type.app.Dog;
+import animal.type.app.Fish;
 import org.arrayutil.app.ArrayUtil;
 
+import java.util.ArrayList;
+import java.util.Arrays;
+
+record GroceryItem(String name, String type, int count) {
+    public GroceryItem(String name) {
+        this(name, "Dairy", 1);
+    }
+}
+
 public class Main {
     public static void main(String[] args) {
-        int[] arr = ArrayUtil.getRandomArray(10);
+        /*int[] arr = ArrayUtil.getRandomArray(100);
         ArrayUtil.printArray(arr);
         int secondMax = ArrayUtil.secondMax(arr);
         System.out.println("SecondMax: " + secondMax);
+        System.out.println(ArrayUtil.binarySearch(arr, 15));
         ArrayUtil.bubbleSort(arr);
         ArrayUtil.printArray(arr);
+        Arrays.sort(arr);
+        System.out.println(Arrays.toString(arr));
+        System.out.println(ArrayUtil.binarySearch(arr, 15));*/
+        ArrayList<Animal> animals = new ArrayList<>();
+        Dog dog = new Dog("Golden", "small", 20);
+        Fish fish = new Fish("Brown", "medium", 5);
+
+        animals.add(dog);
+    }
+    /*public static void GroceryItemTest() {
+        Object[] groceryItems = new Object[5];
+        groceryItems[0] = new GroceryItem("milk");
+        groceryItems[1] = new GroceryItem("Dairy", "Dairy", 2);
+    }*/
+    public static void printAnimals(ArrayList<Animal> animals) {
+        for (Animal animal : animals) {
+            animal.eat();
+            animal.move("fast");
+            animal.sleep();
+            animal.move("slow");
+        }
     }
 }

src/animal/type/app/Animal.java

@@ -0,0 +1,19 @@
+package animal.type.app;
+
+public abstract class Animal {
+    private String type;
+    private String size;
+    private int weight;
+    public Animal(String type, String size, int weight) {
+        this.type = type;
+        this.size = size;
+        this.weight = weight;
+    }
+    public abstract void eat();
+    public abstract void sleep();
+    public abstract void move(String speed);
+
+    public String getExplicitType() {
+        return getClass().getSimpleName() + " (" + type + ")";
+    }
+}

src/animal/type/app/Crocodile.java

@@ -0,0 +1,30 @@
+package animal.type.app;
+
+public class Crocodile extends Animal {
+    public Crocodile(String type, String size, int weight) {
+        super(type, size, weight);
+    }
+
+    @Override
+    public void eat() {
+        System.out.println(getExplicitType() + " eats crocodile");
+    }
+
+    @Override
+    public void sleep() {
+        System.out.println(getExplicitType() + " sleeps crocodile");
+    }
+
+    @Override
+    public void move(String speed) {
+        if (speed.equals("miles")) {
+            System.out.println(getExplicitType() + " moves miles crocodile");
+        }
+        else if (speed.equals("kilometers")) {
+            System.out.println(getExplicitType() + " moves kilometers crocodile");
+        }
+        else {
+            System.out.println(getExplicitType() + " moves feet crocodile");
+        }
+    }
+}

src/animal/type/app/Dog.java

@@ -0,0 +1,28 @@
+package animal.type.app;
+
+public class Dog extends Animal{
+
+    public Dog(String type, String size, int weight) {
+        super(type, size, weight);
+    }
+
+    @Override
+    public void eat() {
+        System.out.println(getExplicitType() + " eats the dog");
+    }
+
+    @Override
+    public void sleep() {
+        System.out.println(getExplicitType() + " sleeps the dog");
+    }
+
+    @Override
+    public void move(String speed) {
+        if (speed.equals("slow")) {
+            System.out.println(getExplicitType() + "Walking");
+        }
+        else {
+            System.out.println(getExplicitType() + "Running");
+        }
+    }
+}

src/animal/type/app/Fish.java

@@ -0,0 +1,28 @@
+package animal.type.app;
+
+public class Fish extends Animal {
+
+    public Fish(String type, String size, int weight) {
+        super(type, size, weight);
+    }
+
+    @Override
+    public void eat() {
+        System.out.println(getExplicitType() + " eats fish");
+    }
+
+    @Override
+    public void sleep() {
+        System.out.println(getExplicitType() + " sleeps fish");
+    }
+
+    @Override
+    public void move(String speed) {
+        if (speed.equals("slow")) {
+            System.out.println(getExplicitType() + " lazily swimming");
+        }
+        else {
+            System.out.println(getExplicitType() + " darting frantically");
+        }
+    }
+}