How does a toString method automatically get run without being called when printing an object to the console?

I was wondering exactly how the toString() method runs without being called when printing out a object.

Code visualization:

Without toString() method:

public class Shop
{

  Shop()
  {
  }

  public static void main(String[] args)
  {
    Shop myShop = new Shop();
    System.out.println(myShop);
  }
}

Result: Shop@3421

With toString() method:

public class Shop
{

  Shop()
  {
  }

  public void toString()
  {
    return "I am a shop";
  }

  public static void main(String[] args)
  {
    Shop myShop = new Shop();
    System.out.println(myShop);
  }
}

Result: I am a shop. The toString method ran but was never called? How?

>Solution :

toString does get called – just not by you! println takes an Object as its argument. As Object has a toString method (the default of which you saw when running your first snippet) the println method will call the passed Object‘s toString before putting the output into System.out.