How to create a subclass in C#?

c# oop subclassing

97,783

Solution 1

Do you mean this?

public class Foo
{}

public class Bar : Foo
{}

In this case, Bar is the sub class.

Solution 2

Here is an example of writing a ParentClass and then creating a ChildClass as a sub class.

using System;

public class ParentClass
{
    public ParentClass()
    {
        Console.WriteLine("Parent Constructor.");
    }

    public void print()
    {
        Console.WriteLine("I'm a Parent Class.");
    }
}

public class ChildClass : ParentClass
{
    public ChildClass()
    {
        Console.WriteLine("Child Constructor.");
    }

    public static void Main()
    {
        ChildClass child = new ChildClass();

        child.print();
    }
}

Output:

Parent Constructor.
Child Constructor.
I'm a Parent Class.

Rather than rewriting yet another example of .Net inheritance I have copied a decent example from the C Sharp Station website.

Solution 3

Do you mean class inheritance?

public class SubClass: MasterClass
{
}

Solution 4

This page explains it well:

public class SavingsAccount : BankAccount
{
    public double interestRate;

    public SavingsAccount(string name, int number, int balance, double rate) : base(name, number)
    {
        accountBalance = balance;
        interestRate = rate;
    }

    public double monthlyInterest()
    {
        return interestRate * accountBalance;
    }
}

static void Main()
{
    SavingsAccount saveAccount = new SavingsAccount("Fred Wilson", 123456, 432, 0.02F);

    Console.WriteLine("Interest this Month = " + saveAccount.monthlyInterest());
}

If the monthlyInterest method already exists in the BankAccount class (and is declared abstract, virtual, or override) then the SavingsAccount method definition should include override, as explained here. Not using override to redefine such class methods will result in a CS0108 compiler warning, which can be suppressed by using new as confusingly stated here.