Dictionary<TKey,TValue>.Remove Method

Definition

Overloads

Remove(TKey)

Removes the value with the specified key from the Dictionary<TKey,TValue>.

Remove(TKey, TValue)

Remove(TKey)

Removes the value with the specified key from the Dictionary<TKey,TValue>.

public:
 virtual bool Remove(TKey key);
public bool Remove (TKey key);
abstract member Remove : 'Key -> bool
override this.Remove : 'Key -> bool
Public Function Remove (key As TKey) As Boolean

Parameters

key
TKey

The key of the element to remove.

Returns

true if the element is successfully found and removed; otherwise, false. This method returns false if key is not found in the Dictionary<TKey,TValue>.

Implements

Exceptions

key is null.

Examples

The following code example shows how to remove a key/value pair from a dictionary using the Remove method.

This code example is part of a larger example provided for the Dictionary<TKey,TValue> class (openWith is the name of the Dictionary used in this example).

// Use the Remove method to remove a key/value pair.
Console::WriteLine("\nRemove(\"doc\")");
openWith->Remove("doc");

if (!openWith->ContainsKey("doc"))
{
    Console::WriteLine("Key \"doc\" is not found.");
}
// Use the Remove method to remove a key/value pair.
Console.WriteLine("\nRemove(\"doc\")");
openWith.Remove("doc");

if (!openWith.ContainsKey("doc"))
{
    Console.WriteLine("Key \"doc\" is not found.");
}
' Use the Remove method to remove a key/value pair.
Console.WriteLine(vbLf + "Remove(""doc"")")
openWith.Remove("doc")

If Not openWith.ContainsKey("doc") Then
    Console.WriteLine("Key ""doc"" is not found.")
End If

Remarks

If the Dictionary<TKey,TValue> does not contain an element with the specified key, the Dictionary<TKey,TValue> remains unchanged. No exception is thrown.

This method approaches an O(1) operation.

.NET Core 3.0+ only: this mutating method may be safely called without invalidating active enumerators on the Dictionary<TKey,TValue> instance. This does not imply thread safety.

See also

Remove(TKey, TValue)

public:
 bool Remove(TKey key, [Runtime::InteropServices::Out] TValue % value);
public bool Remove (TKey key, out TValue value);
member this.Remove : 'Key * 'Value -> bool
Public Function Remove (key As TKey, ByRef value As TValue) As Boolean

Parameters

key
TKey
value
TValue

Returns

Applies to