Is it possible to throw an exception from a method of a child class in a base class in C #?

Question

In an interview, the interviewer asked me this question. Can we catch the exception thrown by the method of the child class in the base class? I said no, but he said it was possible. So I want to know if this is possible at all, and if so, please give me some practical example. You do not need to call the base class method. Thank you

Answer 1

Here you go:

public class BaseClass
{
    public void SomeMethod()
    {
        try
        {
            SomeOtherMethod();
        }
        catch(Exception ex)
        {
            Console.WriteLine("Caught Exception: " + ex.Message);
        }
    }

    public virtual void SomeOtherMethod()
    {
        Console.WriteLine("I can be overridden");
    }
}

public class ChildClass : BaseClass
{
    public override void SomeOtherMethod()
    {
        throw new Exception("Oh no!");
    }
}

SomeMethod, , SomeOtherMethod . SomeOtherMethod - , SomeMethod, . , , ( ChildClass, ), , , .

( , ) , , , ( ):

public class BaseClass
{
    public void SomeMethod()
    {
        var thing = new ChildClass();
        try
        {
            thing.ThrowMyException();
        }
        catch(Exception ex)
        {
            Console.WriteLine("Exception caught: " + ex.Message);
        }
    }
}

public class ChildClass : BaseClass
{
    public void ThrowMyException()
    {
        throw new Exception("Oh no!");
    }
}

, BaseClass.SomeMethod, , .

Answer 2

, .

abstract class Base
{
    // A "safe" version of the GetValue method.
    // It will never throw an exception, because of the try-catch.
    public bool TryGetValue(string key, out object value)
    {
        try
        {
            value = GetValue(key);
            return true;
        }
        catch (Exception e)
        {
            value = null;
            return false;
        }
    }

    // A potentially "unsafe" method that gets a value by key.
    // Derived classes can implement it such that it throws an
    // exception if the given key has no associated value.
    public abstract object GetValue(string key);
}

class Derived : Base
{
    // The derived class could do something more interesting then this,
    // but the point here is that it might throw an exception for a given
    // key. In this case, we'll just always throw an exception.
    public override object GetValue(string key)
    {
        throw new Exception();
    }
}