Few extension methods of IEnumerable in C#

public static IEnumerable<string> IfMatchWith(this IEnumerable<string> myList, string itemToMatch)
{
    foreach (var item in myList.Where(item => item == itemToMatch))
        yield return item;
}

public static IEnumerable<string> IfMatchWith(this IEnumerable<string> myList, string itemToMatch)
{
    return myList.Where(item => item == itemToMatch);
}