C# 4.0 – Optional Parameters

Optional parameters - one of the coolest feature in C# 4.0. It is similar to the optional parameters in SQL Server stored procedure.

Since this feature is not in the earlier versions, we need to use method overloading. Now, in C# 4.0 instead of method overloading we can use optional parameters.

How to implement an optional parameters in C# 4.0? Here is a simple example.

public void GetSupplierAddress(int SuppNo, string city = null)

Please note the second parameter. It has the null value as default. It is not possible to assign a value like this in the earlier versions of C#. So while calling this method it is possible to ignore the second parameter.

        SupplierData objSuppliers = new SupplierData(); 
        objSuppliers.GetSupplierAddress(1); 
        objSuppliers.GetSupplierAddress(1, "London");

You can find the source code below.

Source Code - Optional Parameters