Instantiating an object without an assignment

Question

Hi,
I am learning Java. I would like to know what is the significance of instantiating an object without an assignment.
I have created a class TestClass1 with a single constructor that prints a test message.
In TestClass2, if I write "new TestClass1()" rather than "TestClass1 x = new TestClass1()" it still works, and prints the test message.
I would like to know if I do not assign an object at the time of instantiation, it cannot be referenced or reused later, then what is the significance of this type of construct and when it can be useful, and where is the object being held.
public class TestClass1 {
   TestClass1() {
     System.out.println("This is a test message");
public class TestClass2 {
  public static void main (String... args) {
    TestClass1 x = new TestClass1();  //This prints "This is a test message"
    new TestClass1();                 //This also prints "This is a test message"
    String y = new String("abc");  //this makes sense
    //The following does not throw an exception - what purpose could this conceivably serve
    new String("def");               

Answer 1

SRAY01 wrote:
Sorry for using the wrong terminology - I mean a method is invoked rather than instantiated.
A Constructor can be treated as a special type of method to instantiate an object of the class - but it does not have any expressed return type - so I assumed it implicitly returns an object (of same type as the class the contructor belongs to).
But syntactically its usage is sort of similar to invoking a method (apart from the "new" keyword).
I was wondering how is it possible that a constructor or a method with a return value could be called in a code without an assignment. I assumed it should be possible only for void type of methods.
But apparently its a feature of Java. This feature is very different from any programming language I have worked with so far, e.g. PL/SQL where you cannot call a function with a return value without assigment.
No the constructor doesn't 'return' anything.
Construction is done by the new expression.  As PART of the execution of the new expression the constructor is called.  The new expression does other things besides just call the constructor.  For instance it allocates space and it is also responsible for returning the object.  And this is also true for languages like C# and C++ as well.