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:
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