C# Cannot access child public method from abstract parent class object

Question

I\'m learning OOAD and trying to implement class relationship with inheritance but there is an issue here is the code

Parent Class

names         


        

Answer 1

You can only use the functions declared in the class you use.

abstract class Classification
{
  public abstract string type();
}

class PartTime : Classification
{
  public override string type() {...}
  public Job1() {...}
}

class FullTime : Classification
{
  public override string type() {...}
  public Job2() {...}
}

• A object of type Classification can only use the type()
• A object of the type PartTime can use type and Job1()
• A object of the type FullTime can use type and Job2()

If you have an object like this:

Classification classification = new PartTime();

and you don´t know which special type, you have to cast this object to use other methods:

if (classification is PartTime)
{
  ((PartTime)classification).Job1();
}
else if (classification is FullTime)
{
  ((FullTime)classification).Job2();
}

Hope this helps.