Question

My code –

public abstract class Level1Class
{
  protected double num = 0.0D;  
  protected Level1Class(){}
  protected Level1Class(double num){this.num = num;}
  protected abstract methods A, B, C...etc //pseudocode !

}

public class Level2Class extends Level1Class
{
  //NO CONSTRUCTORS HERE
  //BUT, only implementation of methods A,B, C
} 

public class Tester
{
  Level2Class l2c = new Level2Class(10.0D); //This causes the compiler error ! 
}

Can someone tell me why I get this error. I know it will go if I create the necessary constructor in Level2Class. But, I want to know the reason.

Answer 1

Level2Class have a only default constructor which would be implemented by compiler. Level2Class does not have constructor which takes double as parameter.

Level2Class l2c = new Level2Class(10.0D);

This will try to figure out double constructor in Level2Class class which is not available because constructor are not inherited.