public void UnitRdx_RemoveAt()
{
var rd = new RankedDictionary <int, int>();
for (int ii = 0; ii < 5000; ++ii)
{
rd.Add(ii, -ii);
}
for (int i2 = 4900; i2 >= 0; i2 -= 100)
{
rd.RemoveAt(i2);
}
for (int i2 = 0; i2 < 5000; ++i2)
{
if (i2 % 100 == 0)
{
Assert.IsFalse(rd.ContainsKey(i2));
}
else
{
Assert.IsTrue(rd.ContainsKey(i2));
}
}
}
static void Main()
{
#region Ctor0
// Instantiate with four ISO 3166-1 country codes:
var cc = new RankedDictionary <string, string>
{
{ "TO", "Tonga" },
{ "DD", "German Democratic Republic" },
{ "CH", "Switzerland" },
{ "RU", "Burundi" }
};
#endregion
#region Add
// The Add method throws an exception if the new key is
// already in the dictionary.
try
{
cc.Add("DD", "East Germany");
}
catch (ArgumentException)
{
Console.WriteLine("An element with Key = 'DD' already exists.");
}
#endregion
// The Item property is another name for the indexer,
// so you can omit its name when accessing elements.
Console.WriteLine($"For key = 'CH', value = {cc["CH"]}.");
#region Indexer
// The indexer can be used to change the value associated with a key.
cc["RU"] = "Russian Federation";
// The indexer can be used to get a value for a key.
Console.WriteLine($"For key = 'RU', value = {cc["RU"]}.");
// If a key does not exist, setting the indexer for that key
// adds a new key/value pair.
cc["SS"] = "South Sudan";
#endregion
// The indexer throws an exception if the supplied key is
// not in the dictionary.
try
{
Console.WriteLine($"For key = 'ZZ', value = {cc["ZZ"]}.");
}
catch (KeyNotFoundException)
{
Console.WriteLine("Key = 'ZZ' is not found.");
}
#region TryGetValue
// When a program often has to try keys that are usually not in the
// dictionary, TryGetValue can be a more efficient way to get values.
if (cc.TryGetValue("ZZ", out string value))
{
Console.WriteLine($"For key = 'ZZ', value = {value}.");
}
else
{
Console.WriteLine("Key = 'ZZ' is not found.");
}
#endregion
#region ContainsKey
// ContainsKey can be used to test keys before inserting them.
if (!cc.ContainsKey("GG"))
{
cc.Add("GG", "Guernsey");
Console.WriteLine($"Value added for key = 'GG': {cc["GG"]}");
}
#endregion
// When you use foreach to enumerate dictionary elements,
// the elements are retrieved as KeyValuePair instances.
Console.WriteLine();
foreach (KeyValuePair <string, string> pair in cc)
{
Console.WriteLine($"Key = {pair.Key}, Value = {pair.Value}");
}
#region Values
// To get the values alone, use the Values property.
RankedDictionary <string, string> .ValueCollection vals = cc.Values;
// The elements of the ValueCollection are strongly typed
// with the type that was specified for dictionary values.
Console.WriteLine();
foreach (string val in vals)
{
Console.WriteLine($"Value = {val}");
}
#endregion
#region Keys
// To get the keys alone, use the Keys property.
RankedDictionary <string, string> .KeyCollection keys = cc.Keys;
// The elements of the KeyCollection are strongly typed
// with the type that was specified for dictionary keys.
Console.WriteLine();
foreach (string key in keys)
{
Console.WriteLine($"Key = {key}");
}
#endregion
// Use the Remove method to remove a key/value pair.
Console.WriteLine("\nRemoving 'DD'.");
cc.Remove("DD");
Console.WriteLine("\nChecking if 'DD' exists:");
if (!cc.ContainsKey("DD"))
{
Console.WriteLine(" Key 'DD' not found.");
}
}
/// <summary>Determines whether the dictionary contains the supplied key.</summary> /// <param name="key">The key to locate.</param> /// <returns><b>true</b> if <em>key</em> is contained in the dictionary; otherwise <b>false</b>.</returns> /// <exception cref="ArgumentNullException">When <em>key</em> is <b>null</b>.</exception> public bool Contains(TKey key) => tree.ContainsKey(key);
