C# - When to use override & new
Method in the child class can have a same method name in the base class. You can specify how the methods interact by using override and new keywords. override extend the base class method, and new modifier hides the the child class method that has the same method name as base class.
Example
// Base class
class Car
{
public void DescribeCar()
{
Console.WriteLine("Four wheels and an engine!");
ShowDeatils();
}
public virtual void ShowDetails()
{
Console.WriteLine("Standard transportation!");
}
}
// Child class
class ConvertibleCar : Car
{
public new void ShowDetails()
{
Console.WriteLine("The roof opens up!");
}
}
// Child class
class MiniVan : Car
{
public override ShowDetails()
{
Console.WriteLine("Carries 7 people!");
}
}
class Program
{
static void Main(string args[])
{
var cars = new List<Car>()
{
new Car(),
new ConvertibleCar(),
new MiniVan()
}
foreach (var car in cars)
{
car.DescribeCar();
}
}
}
/*
Ouput:
Four wheels and an engine!
Standard transportation!
Four wheels and an engine!
Standard transportation!
Four whiles and an engine!
Carries 7 people!
*/
More details in When to use oerride and new keywords