// Should you make a constructor $private$? This questions pops up a lot 
// in CS100:

/* Opinion by DIS:
 * At a CS100 level, make your constructors $public$ or default visibility.
 * A $private$ constructor will hide the ability to create an object, and since
 * you need to practice making objects, $private$ defeats the purpose.
 */

/* Opinion by Niranjan, a former CS100 TA:
 * I saw a comment in the private_constructor.java file that said
 * that usually you don't make constructors private and it seemed
 * to give the impression that private constructors lead to errors. I was
 * worried by this because I have often seen private constructors being
 * used in industrial java code. They are useful to create special objects
 * of a class for use inside the class where the user should have no
 * knowledge of such special objects. They are also sometimes used for the
 * very purpose that you have shown in the example: to prevent the
 * use of a certain form of creating the object. Actually this is usually
 * done in C++ to prevent the compiler from creating a default constructor
 * that the user can use (i.e forcing the object to be always be created
 * using non-default constructors.)
 */

class Test {
    public int k = 1;
    private Test() {}
}

public class private_constructor {
    public static void main(String[] args) {
	System.out.println(new Test().k);
    }
}

/* Output: 
private_constructor.java:8: No constructor matching Test() found in class Test.
        System.out.println(new Test().k);
                           ^
1 error
*/