Changed methods in super to void

src/main/java/core/basesyntax/Bulldozer.java

@@ -2,12 +2,12 @@
 
 public class Bulldozer extends Machine {
  @Override
- public String doWork() {
- return "Bulldozer started its work.";
+ public void doWork() {
+ System.out.println("Bulldozer started its work.");
  }
 
  @Override
- public String stopWork() {
- return "Bulldozer stopped its work.";
+ public void stopWork() {
+ System.out.println("Bulldozer stopped its work.");
  }
 }

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

@@ -2,12 +2,12 @@
 
 public class Excavator extends Machine {
  @Override
- public String doWork() {
- return "Excavator started its work.";
+ public void doWork() {
+ System.out.println("Excavator started its work.");
  }
 
  @Override
- public String stopWork() {
- return "Excavator stopped its work.";
+ public void stopWork() {
+ System.out.println("Excavator stopped its work.");
  }
 }

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

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

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

@@ -4,8 +4,8 @@ public class MainApp {
  public static void main(String[] args) {
  Machine[] machines = {new Bulldozer(), new Excavator(), new Truck()};
  for (Machine machine : machines) {
- System.out.println(machine.doWork());
- System.out.println(machine.stopWork());
+ machine.doWork();
+ machine.stopWork();
  }
  }
 }

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

@@ -2,12 +2,12 @@
 
 public class Truck extends Machine {
  @Override
- public String doWork() {
- return "Truck started its work.";
+ public void doWork() {
+ System.out.println("Truck started its work.");
  }
 
  @Override
- public String stopWork() {
- return "Truck stopped its work.";
+ public void stopWork() {
+ System.out.println("Truck stopped its work.");
  }
 }