Dictionary<TKey,TValue>.Remove Method

Definition

Namespace:

System.Collections.Generic

Assemblies:

netstandard.dll, System.Collections.dll

Overloads

Remove(TKey)	Removes the value with the specified key from the Dictionary<TKey,TValue>.
Remove(TKey, TValue)	Removes the value with the specified key from the Dictionary<TKey,TValue>, and copies the element to the value parameter.

Remove(TKey)

Source:

Dictionary.cs

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

C#

public bool Remove(TKey key);

Parameters

key

TKey

The key of the element to remove.

Returns

Boolean

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

Remove(TKey)

Exceptions

ArgumentNullException

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).

C#

// 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.");
}

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

• Add(TKey, TValue)
• Remove(TKey)

Remove(TKey, TValue)

Source:

Dictionary.cs

Removes the value with the specified key from the Dictionary<TKey,TValue>, and copies the element to the value parameter.

C#

public bool Remove(TKey key, out TValue value);

Parameters

key

TKey

The key of the element to remove.

value

TValue

The removed element.

Returns

Boolean

true if the element is successfully found and removed; otherwise, false.

Exceptions

ArgumentNullException

key is null.