OOP basic program

src/main/java/core/basesyntax/Machine.java

@@ -0,0 +1,7 @@
+package core.basesyntax;
+
+public abstract class Machine {
+    public abstract void doWork();
+    public abstract void stopWork();
+}
+

src/main/java/core/basesyntax/Machines.java

@@ -0,0 +1,40 @@
+package core.basesyntax;
+
+public abstract class Machines {
+    public static class Truck extends Machine {
+        @Override
+        public void doWork() {
+            System.out.println("Truck started its work");
+    }
+        @Override
+        public void stopWork() {
+            System.out.println("Truck stopped working");
+        }
+    }
+
+    public static class Bulldozer extends Machine {
+        @Override
+        public void doWork() {
+            System.out.println("Bulldozer started its work");
+        }
+        @Override
+        public void stopWork() {
+            System.out.println("Bulldozer stopped working");
+        }
+    }
+
+    public static class Excavator extends Machine {
+        @Override
+        public void doWork() {
+            System.out.println("Excavator started its work");
+        }
+        @Override
+        public void stopWork() {
+            System.out.println("Excavator stopped working");
+        }
+    }
+
+
+}
+
+

src/main/java/core/basesyntax/MainApp.java

@@ -1,5 +1,20 @@
 package core.basesyntax;
 
 public class MainApp {
+    public static void main (String[] args) {
+        Machine[] machines = {
+                new Machines.Truck(),
+                new Machines.Bulldozer(),
+                new Machines.Excavator()
+        };
+
+        for(Machine machine : machines) {
+            machine.doWork();
+        }
+
+        for(Machine machine : machines) {
+            machine.stopWork();
+        }
+    }
 
 }