java puzzlers from oca part 6

Even for new Java developers, constructors are probably no big mystery. In essence, when you create an instance of a class, the constructor of this class is started. In the 6th part of Java Puzzlers series, we will see a case related to constructors.

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print?

01	public class Puzzler {

02

03	public Puzzler(){

04	System.out.println("Puzzler no arg constructor");

05

}

06

07	public static void main(String[] args){

08	Puzzler puzzler = new Puzzler();

09

}

10

}

In the example above Puzzler() constructor will start and "Puzzler no arg constructor" will be printed to the screen. Now lets see a new example.

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print?

01	public class Puzzler {

02

03	public void Puzzler(){

04	System.out.println("Puzzler no arg constructor?");

05

}

06

07	public static void main(String[] args){

08	Puzzler puzzler = new Puzzler();

09

}

10

}

As you can see we added a return value to the constructor of Puzzler and you may expect that "Puzzler no arg constructor?" will get printed but this is not right. When we add a return value to the constuctor, it stops being a constructor. So it won't get started when a new instance is created.