using System;
using System.Collections.Generic;
using System.Text;
class DatabaseReader {
// Nullable data field.
public int? numbericValue;
public bool? boolValue = true;
// Note the nullable return type.
public int? GetIntFromDatabase() { return numbericValue; }
// Note the nullable return type.
public bool? GetBoolFromDatabase() { return boolValue; }
}
class Program {
static void Main(string[] args) {
DatabaseReader dr = new DatabaseReader();
int? i = dr.GetIntFromDatabase();
if (i.HasValue)
Console.WriteLine("Value of 'i' is: {0}", i);
else
Console.WriteLine("Value of 'i' is undefined.");
// Get bool from 'database'.
bool? b = dr.GetBoolFromDatabase();
if (b != null)
Console.WriteLine("Value of 'b' is: {0}", b);
else
Console.WriteLine("Value of 'b' is undefined.");
// If the value from GetIntFromDatabase() is null,
// assign local variable to 100.
int? myData = dr.GetIntFromDatabase() ?? 100;
Console.WriteLine("Value of myData: {0}", myData);
}
}