can we call a constructor from another one? how?

Answer 1

Yes!!, lets take a simple example below:

public class Tester{
int i;
double j;
public Tester(double j){
i = -8;
this.j= j;
}

public Tester(int i, double j){
this(j); // this is calling the above constructor here
this.i = i;
}

}

Essentially use the "this" keyword followed by parenthesis and pass arguments if needed.

Answer 2

thanks loads:)