In multi threaded environment, it should be synchronized externally.
The iterators returned by LinkedList class’s iterator and listIterator methods are fail-fast.
LinkedList class can contain duplicate elements.
2. Class hierarchy of LinkedList:
Fig 1: Class hierarchy of LinkedList class
3. Add or insert methods of LinkedList in java (with example):
No.
Method Name
Description
1
boolean add(E e)
Appends the specified element to the end of this list.
2
void add(int index, E element)
Inserts the specified element at the specified position in this list.
3
boolean addAll(Collection<? extends E> c)
Appends all of the elements in the specified collection to the end of this list, in the order that they are returned by the specified collection's iterator.
4
boolean addAll(int index, Collection<? extends E> c)
Inserts all of the elements in the specified collection into this list, starting at the specified position.
5
void addFirst(E e)
Inserts the specified element at the beginning of this list.
6
void addLast(E e)
Appends the specified element to the end of this list.
4. Program – Add or insert nodes to linkedlist in java (example)
package org.learn.collection.list.linkedlist;
import java.util.LinkedList;
public class DemoAddToLinkedList {
public static void main(String[] args) {
LinkedList<String> linkedList = new LinkedList<>();
linkedList.add("canoe");
System.out.println("Demo of add methods of LinkedList class: ");
demoAddMethod(linkedList);
}
private static void demoAddMethod(LinkedList<String> linkedList) {
// [canoe]
System.out.println("1. Orignal LinkedList:" + linkedList);
linkedList.add(0, "archery");
linkedList.add(2, "canoe");
// [archery, canoe, canoe]
System.out.println("2. Added element at 0 and 2 index: " + linkedList);
linkedList.add("diving");
// [archery, canoe, canoe, diving]
System.out.println("3. Added element in list: " + linkedList);
LinkedList<String> addElementsList = new LinkedList<>();
addElementsList.add("squash");
addElementsList.add("bowling");
// It will add elements to last of list
linkedList.addAll(addElementsList);
// [archery, canoe, canoe, diving, squash, bowling]
System.out.println("4. Added another list : " + linkedList);
LinkedList<String> anotherList = new LinkedList<>();
anotherList.add("golf");
anotherList.add("judo");
// It will add elements from index 1
linkedList.addAll(1, anotherList);
// [archery, golf, judo, canoe, canoe, diving, squash, bowling]
System.out.println("5. Added another list at index 1 : " + linkedList);
// It will add element before head i.e. first element of list of list
linkedList.addFirst("squash");
// [squash, archery, golf, judo, canoe, canoe, diving, squash, bowling]
System.out.println("6. Added element before head : " + linkedList);
// It will add elements to last of list
linkedList.addLast("judo");
// [squash, archery, golf, judo, canoe, canoe, diving, squash, bowling, judo]
System.out.println("7. Added element to after tail node : " + linkedList);
}
}
5. Output – Add or insert elements/ nodes to linkedlist in java
Demo of add methods of LinkedList class:
1. Orignal LinkedList:[canoe]
2. Added element at 0 and 2 index: [archery, canoe, canoe]
3. Added element in list: [archery, canoe, canoe, diving]
4. Added another list : [archery, canoe, canoe, diving, squash, bowling]
5. Added another list at index 1 : [archery, golf, judo, canoe, canoe, diving, squash, bowling]
6. Added element before head : [squash, archery, golf, judo, canoe, canoe, diving, squash, bowling]
7. Added element to after tail node : [squash, archery, golf, judo, canoe, canoe, diving, squash, bowling, judo]
