A HashSet is an unordered collection of the unique elements. It comes under System.Collections.Generic namespace. It is used in a situation where we want to prevent duplicates from being inserted in the collection. As far as performance is concerned, it is better in comparison to the list. HashSet<T>.Remove(T) method is used to remove the specified element from a HashSet<T> object.
Syntax:
public bool Remove (T item);
Here, item is the element which is to be removed.
Return Value: The method returns True if the element is successfully found and removed and returns False if item is not found in the HashSet<T> object.
Below examples illustrate the use of HashSet.Remove(T) Method:
Example 1:
// C# code to remove the specified // element from a HashSet using System;
using System.Collections.Generic;
class GFG {
// Driver code
public static void Main()
{
// Creating a HashSet of integers
HashSet< int > mySet = new HashSet< int >();
// Inserting even numbers less than
// equal to 20 in HashSet mySet
for ( int i = 0; i < 10; i++) {
mySet.Add(i * 2);
}
Console.WriteLine("The elements in HashSet are : ");
// Displaying the elements in HashSet
foreach ( int i in mySet)
{
Console.WriteLine(i);
}
// Displaying the number of elements in HashSet
Console.WriteLine("Number of elements are : " + mySet.Count);
// Removing the element 10 if present
if (mySet.Contains(10)) {
mySet.Remove(10);
}
Console.WriteLine("The elements in HashSet are : ");
// Displaying the elements in HashSet
foreach ( int i in mySet)
{
Console.WriteLine(i);
}
// Displaying the number of elements in HashSet
Console.WriteLine("Number of elements are : " + mySet.Count);
}
} |
The elements in HashSet are : 0 2 4 6 8 10 12 14 16 18 Number of elements are : 10 The elements in HashSet are : 0 2 4 6 8 12 14 16 18 Number of elements are : 9
Example 2:
// C# code to remove the specified // element from a HashSet using System;
using System.Collections.Generic;
class GFG {
// Driver code
public static void Main()
{
// Creating a HashSet of strings
HashSet< string > mySet = new HashSet< string >();
// Inserting elements into HashSet
mySet.Add("Data Structures");
mySet.Add("Algorithms");
mySet.Add("Java");
mySet.Add("Puzzles");
mySet.Add("Coding");
Console.WriteLine("The elements in HashSet are : ");
// Displaying the elements in HashSet
foreach ( string i in mySet)
{
Console.WriteLine(i);
}
// Displaying the number of elements in HashSet
Console.WriteLine("Number of elements are : " + mySet.Count);
// Removing the element "JavaScript" if present
if (mySet.Contains("JavaScript")) {
mySet.Remove("JavaScript");
}
Console.WriteLine("The elements in HashSet are : ");
// Displaying the elements in HashSet
foreach ( string i in mySet)
{
Console.WriteLine(i);
}
// Displaying the number of elements in HashSet
Console.WriteLine("Number of elements are : " + mySet.Count);
}
} |
The elements in HashSet are : Data Structures Algorithms Java Puzzles Coding Number of elements are : 5 The elements in HashSet are : Data Structures Algorithms Java Puzzles Coding Number of elements are : 5
Reference: