Java – How to remove elements from LinkedList

In this article, we will discuss how to remove elements from LinkedList

There are different methods available in LinkedList class for removing elements as listed below,

  • removeFirst(); – removes 1st or top element from LinkedList
  • removeLast(); – removes last or bottom element from LinkedList
  • remove(int index); – removes element from LinkedList at the specified index position, where index starts from ZERO
  • remove(Object o); – removes specified element/object from LinkedList
  • removeFirstOccurrence(Object o); – removes 1st occurrence of specified element from LinkedList
  • removeLastOccurrence(Object o); – removes last occurrence of specified element from LinkedList
  • remove(); – retrieves and removes the head/first element from LinkedList

Example for LinkedList remove operation

  • There are initially 7 elements added to LinkedList
  • after 1st removal using removeFirst(); there are only 6 elements remaining i.e.; removes “Sundar Pichai” from LinkedList
  • In 2nd removal using removeLast(); method there are only 5 elements remaining i.e.; removes “Chandrasekaran Natarajan” from LinkedList
  • Similarly, after 3rd removal using index-position of remove(int index); method, there are only 4 elements remaining in LinedkList i.e.; removes “Shantanu Narayen” from LinkedList
  • At last after 4th removal using remove(Object o); only 3 elements remaining in the LinkedList which is lastly printed to console i.e.; removes “Shiv Nadar” from LinkedList
  • Note: while going through below example, current LinkedList elements will always be previous iteration printed to console
package net.bench.resources.collection.example;

import java.util.LinkedList;

public class LinkedListRemoveOperation {

	public static void main(String[] args) {

		// creating LinkedList object of type String
		LinkedList<String> ceo = new LinkedList<String>();

		// adding elements to LinkedList object
		ceo.add("Sundar Pichai");
		ceo.add("Satya Nadella");  
		ceo.add("Shiv Nadar");  
		ceo.add("Shantanu Narayen");
		ceo.add("Narayan Murthy");
		ceo.add("Francisco D’Souza");
		ceo.add("Chandrasekaran Natarajan");

		// Iterating using enhanced for-loop
		System.out.println("Iterating LinkedList elements - "
				+ "Before Remove :\n");
		for(String s : ceo){
			System.out.println(s);
		}

		// 1.A removes FIRST element from current LinkedList
		ceo.removeFirst();

		// 1.B Iterating using enhanced for-loop
		System.out.println("\n\nIterating CURRENT LinkedList elements - "
				+ "After Removing 1st or top element :\n");
		for(String s : ceo){
			System.out.println(s);
		}


		// 2.A removes LAST element from current LinkedList
		ceo.removeLast();

		// 2.B Iterating using enhanced for-loop
		System.out.println("\n\nIterating CURRENT LinkedList elements - "
				+ "After Removing last or bottom element :\n");
		for(String s : ceo){
			System.out.println(s);
		}

		// 3.A removing element at 2nd index from current LinkedList
		ceo.remove(2);

		// 3.B Iterating using enhanced for-loop
		System.out.println("\n\nIterating CURRENT LinkedList elements - "
				+ "After Removing element at index-2 :\n");
		for(String s : ceo){
			System.out.println(s);
		}

		// 4.A removing element "Shiv Nadar" from current LinkedList
		ceo.remove("Shiv Nadar");

		// 4.B Iterating using enhanced for-loop
		System.out.println("\n\nIterating CURRENT LinkedList elements - "
				+ "After Removing element 'Shiv Nadar' :\n");
		for(String s : ceo){
			System.out.println(s);
		}
	}
}

Output:

Iterating LinkedList elements - Before Remove :

Sundar Pichai
Satya Nadella
Shiv Nadar
Shantanu Narayen
Narayan Murthy
Francisco D’Souza
Chandrasekaran Natarajan


Iterating CURRENT LinkedList elements - After Removing 1st or top element :

Satya Nadella
Shiv Nadar
Shantanu Narayen
Narayan Murthy
Francisco D’Souza
Chandrasekaran Natarajan


Iterating CURRENT LinkedList elements - After Removing last or bottom element :

Satya Nadella
Shiv Nadar
Shantanu Narayen
Narayan Murthy
Francisco D’Souza


Iterating CURRENT LinkedList elements - After Removing element at index-2 :

Satya Nadella
Shiv Nadar
Narayan Murthy
Francisco D’Souza


Iterating CURRENT LinkedList elements - After Removing element 'Shiv Nadar' :

Satya Nadella
Narayan Murthy
Francisco D’Souz

References:

Happy Coding !!
Happy Learning !!

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