What is LinkedList ?
LinkedList is a doubly-linked list implementation of the List and Deque interfaces.
How to perform Basic Operations in LinkedList?
Basic Operations are:
- creating object for LinkedList
- adding objects into LinkedList
- searching an object in LinkedList
- whether it is listed under this LinkedList instance or not
- checking whether the LinkedList is empty or not
- Get the size of the LinkedList
Basic Operations
import java.util.LinkedList;
public class MyBasicOperations {
public static void main(String a[]){
LinkedList ll = new LinkedList();
ll.add("Orange");
ll.add("Apple");
ll.add("Grape");
ll.add("Banana");
System.out.println(ll);
System.out.println("Size of the linked list: "+ll.size());
System.out.println("Is LinkedList empty? "+ll.isEmpty());
System.out.println("Does LinkedList contains 'Grape'? "+ll.contains("Grape"));
}
}
Try it Yourself
How to add all elements of a list to LinkedList?
Example
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
public class MyLinkedListNewCollection {
public static void main(String a[]){
LinkedList arrl = new LinkedList();
//adding elements to the end
arrl.add("First");
arrl.add("Second");
arrl.add("Third");
arrl.add("Random");
System.out.println("Actual LinkedList:"+arrl);
List list = new ArrayList();
list.add("one");
list.add("two");
arrl.addAll(list);
System.out.println("After Copy: "+arrl);
}
}
Try it Yourself
How to reverse LinkedList content?
We can reverse the content by calling Collections.reverse() method.
We have to pass LinkedList instance to this method, which reverses the content.
Example
import java.util.Collections;
import java.util.LinkedList;
public class MyLinkedListReverse {
public static void main(String a[]){
LinkedList list = new LinkedList();
list.add("Java");
list.add("Cric");
list.add("Play");
list.add("Watch");
list.add("Glass");
Collections.reverse(list);
System.out.println("Results after reverse operation:");
for(String str: list){
System.out.println(str);
}
}
}
Try it Yourself
How to swap two elements in a LinkedList?
By calling Collections.swap() method we can swap two elements of the LinkedList.
We have to pass the indexes which we need to swap.
Example
import java.util.Collections;
import java.util.LinkedList;
public class MyLinkedListSwap {
public static void main(String a[]){
LinkedList list = new LinkedList();
list.add("Java");
list.add("Cric");
list.add("Play");
list.add("Watch");
list.add("Glass");
list.add("Movie");
list.add("Girl");
Collections.swap(list, 2, 5);
System.out.println("Results after swap operation:");
for(String str: list){
System.out.println(str);
}
}
}
Try it Yourself
How to read first element from LinkedList?
LinkedList provides few methods to read first element, those methods are:
element(): Retrieves, but does not remove, the head (first element) of this list.
getFirst(): Returns the first element in this list.
peek(): Retrieves, but does not remove, the head (first element) of this list.
peekFirst(): Retrieves, but does not remove, the first element of this list, or returns null if this list is empty.
Example
import java.util.LinkedList;
public class MyFirstElement {
public static void main(String a[]){
LinkedList arrl = new LinkedList();
arrl.add("First");
arrl.add("Second");
arrl.add("Third");
arrl.add("Random");
System.out.println("First Element: "+arrl.element());
System.out.println("First Element: "+arrl.getFirst());
System.out.println("First Element: "+arrl.peek());
System.out.println("First Element: "+arrl.peekFirst());
}
}
Try it Yourself
How to add element at first position in LinkedList?
LinkedList provides few methods to add element at first position, those methods are:
addFirst(): Inserts the specified element at the beginning of this list.
offerFirst(): Inserts the specified element at the front of this list.
Example
import java.util.LinkedList;
public class MyAddFirst {
public static void main(String a[]){
LinkedList arrl = new LinkedList();
arrl.add("First");
arrl.add("Second");
arrl.add("Third");
arrl.add("Random");
System.out.println(arrl);
System.out.println("Adding element at first position...");
arrl.addFirst("I am first");
System.out.println(arrl);
System.out.println("Adding element at first position...");
arrl.offerFirst("I am first - 2");
System.out.println(arrl);
}
}
Try it Yourself
How to add element at last position in LinkedList?
LinkedList provides few methods to add element at last position, those methods are:
addLast(): Appends the specified element to the end of this list.
offerLast(): Inserts the specified element at the end of this list.
offer(): Adds the specified element as the tail (last element) of this list.
Example
import java.util.LinkedList;
public class MyAddLast {
public static void main(String a[]){
LinkedList arrl = new LinkedList();
arrl.add("First");
arrl.add("Second");
arrl.add("Third");
arrl.add("Random");
System.out.println(arrl);
System.out.println("Adding element at last position...");
arrl.addLast("I am last");
System.out.println(arrl);
System.out.println("Adding element at last position...");
arrl.offerLast("I am last - 1");
System.out.println(arrl);
System.out.println("Adding element at last position...");
arrl.offer("I am last - 2");
System.out.println(arrl);
}
}
Try it Yourself
Solve this!!
#20080,20081,20082,20083- Collection
- ArrayList
- LinkedList
- Vector
- HashSet
- Conditional Statements
- Classes and Objects
- Inheritance
- Packages
- Exception Handling
- Threads
- TreeSet
- LinkedHashSet
- HashMap
- TreeMap
- LinkedHashMap
- HashTable
- Iterator and ListIterator
- String
- Scanner
- Array Small Programs
- Introduction
- Variables
- DataTypes
- Operators
- Conditional Statements
- Loop
- Arrays
- Object Oriented Programming
- Classes and Objects
- Access Modifiers
- Methods
- Abstraction
- Constructor
- Packages
- StringBuffer
- Inheritance
- StringBuilder
- Encapsulation
- Java IO
- Polymorphism
- Interface
- Types Of Variables
- Static Keyword
- Final Keyword
- Super Keyword
- This Keyword
- Exception Handling