Question

I’ve found a task on some Java programming competition. One must create class Sentence with only one argument ‘text’ and only one constructor. Here’s sample test code :

 Sentence s1=new Sentence("only","CAT"),
      s2=new Sentence("and", 2, "mice"),
      s3=new Sentence(s1,s2,"completely","alone"),
      s4=new Sentence(s3, "on the ", new Integer(32), "th street");

 System.out.println(s1); Only cat.
 System.out.println(s2); Only cat and 2 mice.
 System.out.println(s3); Only cat and 2 mice completely alone.
 System.out.println(s4); Only cat and 2 mice completely alone on the 32th street.

How one contructor can serve different sets of arguments ? Is there something like dynamical constructor which recognizes sent values?

Answer 1

Make use of varargs.

public class Sentence {

    public Sentence(Object... text) {
        // ...
    }

}

Fill in the constructor logic yourself. It may however become a bit awful to determine all the types. You could make use of Object#toString() and let the Sentence class implement one as well.