/// <summary>Given a list interface of items, return a random item from the List.</summary>
/// <typeparam name="T">The type of the item in <paramref name="listToGetFrom" />.</typeparam>
/// <param name="listToGetFrom">The list to extract a random item from.</param>
/// <returns>The randomized item to return from the list.</returns>
public static T GetRandomItem <T>(this IList <T> listToGetFrom)
{
int index = NumberRandomizer.Next(0, listToGetFrom.Count);
if (listToGetFrom.HasIndex(index))
{
return(listToGetFrom[index]);
}
throw new IndexOutOfRangeException("We tried to get an item from a list at an index" + "that was" +
"out of range!");
}
/// <summary>Given a List, shuffle and return it.</summary>
/// <typeparam name="T">The type of object within the given list.</typeparam>
/// <param name="listToShuffle">The list we are to shuffle before returning.</param>
/// <returns>The newly shuffled list.</returns>
public static IList <T> Shuffle <T>(this IList <T> listToShuffle)
{
int n = listToShuffle.Count;
while (n > 1)
{
n--;
int k = NumberRandomizer.Next(n + 1);
T value = listToShuffle[k];
listToShuffle[k] = listToShuffle[n];
listToShuffle[n] = value;
}
return(listToShuffle);
}
/// <summary>Given an Array of items, return a random item from the List.</summary>
/// <typeparam name="T">The type of item in the given <paramref name="lst" />.</typeparam>
/// <param name="lst">The list to get a random item from.</param>
/// <returns>The random item as returned from <paramref name="lst" />.</returns>
public static T GetRandomItem <T>(this Array lst)
{
return((T)lst.GetValue(NumberRandomizer.Next(0, lst.Length)));
}
/// <summary>Given an ArrayList of items, return a random item from the List.</summary>
/// <typeparam name="T">The type of item in the list <paramref name="lst" />.</typeparam>
/// <param name="lst">The list to extract a random item from.</param>
/// <returns>A random item of type <see cref="T" /> from the list.</returns>
public static T GetRandomItem <T>(this ArrayList lst)
{
return((T)lst[NumberRandomizer.Next(0, lst.Count)]);
}
/// <summary>Given an array of items, return a random item from the List.</summary>
/// <typeparam name="T">The type of item in the array <paramref name="lst" />.</typeparam>
/// <param name="lst">The list to extract a random item from.</param>
/// <returns>The randomized item of type <see cref="T" /> to return from the array.</returns>
public static T GetRandomItem <T>(this T[] lst)
{
return(lst[NumberRandomizer.Next(0, lst.Length)]);
}
/// <summary>Given a HashSet of items, return a random item from the List.</summary>
/// <param name="lst">The list to extract a random item from.</param>
/// <typeparam name="T">The type of the item in the <paramref name="lst" />.</typeparam>
/// <returns>The item of type <see cref="T" /> returned by the randomizer.</returns>
public static T GetRandomItem <T>(this HashSet <T> lst)
{
return(lst.ToList()[NumberRandomizer.Next(0, lst.Count)]);
}
