Why to mark constructor as private in Java ?

Question

I know the constructor in Java can be marked as private, but I don't know why to do that ? What is the purpose of private constructor ? Please provide an example.

Answer 1

Example where you could use a private constructor: Singleton pattern.
https://www.sololearn.com/discuss/129670/?ref=app
https://www.sololearn.com/discuss/380564/?ref=app
and many more threads.