Create immutable object, instantiated without new

No, you can't create a class that's instantiated just with = operator because you can't overload an operator in Java like you can in C++ or C# (see Operator overloading in Java).

Strings are instantiated when you use "something" only if they do not already exist in memory, so you get a reference to the same exact String object each time you write "something".

For example, if you do:

String a = "something";
String b = "something";

Then

a == b; // will be true.

You can take a look at these questions to learn more about how String objects work:

• Strings are objects in Java, so why don't we use 'new' to create them?

• What is the difference between "text" and new String("text")?

• What is Java String interning?

Because Java does not support user-defined Operator Overloading a new instance can not be created with = Operator.

Check out Why doesn't Java offer operator overloading? for more information