Created class Machine containing methods public abstract void doWork(…

…) and public abstract void stopWork().

Add classes Truck, Bulldozer, Excavator that will inherit from Machine and override doWork() and stopWork() methods.
In Main class was created Machine array with Truck, Buldozer and Excavator and call methods doWork() and stopWork() in a loop.

src/main/java/core/basesyntax/Buldozer.java

@@ -1,9 +1,11 @@
 package core.basesyntax;
+
 public class Buldozer extends  Machine{
     @Override
     public void doWork() {
         System.out.println("Buldozer started work");
     }
+
     @Override
     public void stopwork() {
         System.out.println("Buldozer stopped work");

src/main/java/core/basesyntax/Excavator.java

@@ -1,9 +1,11 @@
 package core.basesyntax;
+
 public class Excavator extends Machine {
     @Override
     public void doWork() {
         System.out.println("Excavator started work");
     }
+
     @Override
     public void stopwork() {
         System.out.println("Excavastor stopped work");

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

@@ -1,6 +1,8 @@
 package core.basesyntax;
+
 public abstract class Machine {
     public abstract void doWork();
+
     public abstract void stopwork();
 
 }

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

@@ -1,8 +1,10 @@
 package core.basesyntax;
+
 public class MainApp {
     Truck truck = new Truck();
     Buldozer buldozer = new Buldozer();
     Excavator excavator = new Excavator();
+
     public void work() {
         Machine [] machine = new Machine[] {truck, buldozer, excavator};
         for (int i = 0; i < machine.length; i++) {

src/main/java/core/basesyntax/Truck.java

@@ -1,9 +1,11 @@
 package core.basesyntax;
+
 public class Truck extends Machine{
     @Override
     public void doWork() {
         System.out.println("Truck started work");
     }
+
     @Override
     public void stopwork() {
         System.out.println("Truck stopped work");