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How to Delete User Defined Objects from LinkedHashSet?

  • Last Updated : 28 Jun, 2021

The LinkedHashSet is an ordered version of HashSet that maintains a doubly-linked List across all elements. When the iteration order is needed to be maintained this class is used. When iterating through a HashSet the order is unpredictable, while a LinkedHashSet lets us iterate through the elements in the order in which they were inserted. 

Example:

Input: ["Geeks", "for", "geeks"]
DELETE = "geeks"
Output: "Geeks"
    "for"

Input: [1, 2, 3, 4, 5]
DELETE = 2
Output: [1, 3, 4, 5]

There are two ways by which we can delete elements from LinkedHashSet:

  1. Using remove() Method
  2. Using clear() Method

Method 1: remove() methods are used to delete a specific element from a LinkedHashSet object.

Syntax:



LinkedHashSet.remove(Object O)

Parameters: The parameter O is of the type of LinkedHashSet and specifies the element to be removed from the LinkedHashSet.

Return Value: This method returns True if the specified element is present in the LinkedHashSet otherwise it returns False.

Java




// Java program  to delete user defined 
// objects from LinkedHashSet
  
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
    {
  
        LinkedHashSet<String> lset
            = new LinkedHashSet<String>();
  
        // add elements to HashSet
        lset.add("GEEKS");
        lset.add("FOR");
        lset.add("GEEKS");
  
        // Displaying the LinkedHashSet Before Deleting
        System.out.println("Before deleting an element :");
        System.out.println(lset);
  
        // remove() method to delete an element from
        // LinkedHashSet
        lset.remove("FOR");
  
        // Displaying the LinkedHashSet After Deleting
        System.out.println("After deleting an element:");
        System.out.println(lset);
    }
}
Output
Before deleting an element :
[GEEKS, FOR]
After deleting an element:
[GEEKS]

Method 2: clear() method is used to delete all element from LinkedHashSet.  The set will be empty after this call returns.

Syntax:

public void clear()

Return Value: This method does not return anything.

Below are the examples to illustrate the clear() method.

Java




// Java program to delete elements
// from LinkedHashSet
  
import java.util.*;
import java.util.LinkedHashSet;
  
public class GFG {
    public static void main(String[] args)
    {
  
        LinkedHashSet<String> l_set
            = new LinkedHashSet<String>();
  
        // add elements to HashSet
        l_set.add("GEEKS");
        l_set.add("FOR");
        l_set.add("GEEKS");
  
        // Displaying the LinkedHashSet Before Deleting
        System.out.println("Before deleting an element :");
        System.out.println(l_set);
  
        // clear() method to delete all element from
        // LinkedHashSet
        l_set.clear();
  
        // Displaying an empty LinkedHashSet After Deleting
        System.out.println("After deleting all element:");
        System.out.println(l_set);
    }
}
Output
Before deleting an element :
[GEEKS, FOR]
After deleting all element:
[]

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