Java.util.LinkedList.get(), getFirst(), getLast() in Java
Last Updated :
30 Mar, 2023
In Java, the LinkedList class provides several methods for accessing the elements in the list. Here are the methods for getting the elements of a LinkedList:
- get(int index): This method returns the element at the specified position in the LinkedList. The index parameter is zero-based, so the first element has an index of 0.
- getFirst(): This method returns the first element in the LinkedList. If the LinkedList is empty, a NoSuchElementException is thrown.
- getLast(): This method returns the last element in the LinkedList. If the LinkedList is empty, a NoSuchElementException is thrown.
Here’s an example code that demonstrates the use of these methods:
Java
import java.util.*;
public class LinkedListget2 {
public static void main(String[] args)
{
LinkedList<String> list = new LinkedList<String>();
list.add( "Geeks" );
list.add( "4" );
list.add( "Geeks" );
list.add( "8" );
System.out.println( "The elements in List are : "
+ list);
System.out.println( "Element at 1st index is : "
+ list.getFirst());
}
}
|
Output
The element at index 2 is: Charlie
The first element of the LinkedList is: Alice
The last element of the LinkedList is: Dave
In this code, we first create a LinkedList of strings, and then add four elements to it using the add() method.
We then use the get(int index) method to get the element at index 2 (which is “Charlie”), and print it to the console using the println() method.
Next, we use the getFirst() method to get the first element of the LinkedList (which is “Alice”), and print it to the console using the println() method.
Finally, we use the getLast() method to get the last element of the LinkedList (which is “Dave”), and print it to the console using the println() method.
The conventional method allowing to get the element at particular index is get(). Though in LinkedList its never possible to achieve this without complete traversal, but this method allows the same. Three variants present, all of which are discussed in this article with Exceptions as well.
1. get(int index) : This method returns the element at the specified position in this list.
Declaration :
public E get(int index)
Parameters :
index : index of the element to return
Return Value :
This method returns the element at the specified position in this list
Exception
IndexOutOfBoundsException : if the index is out of range
Java
import java.util.*;
public class LinkedListget3 {
public static void main(String[] args)
{
LinkedList<String> list = new LinkedList<String>();
list.add( "Geeks" );
list.add( "4" );
list.add( "Geeks" );
list.add( "8" );
System.out.println( "The elements in List are : "
+ list);
System.out.println( "Element at last index is : "
+ list.getLast());
}
}
|
Output
The elements in List are : [Geeks, 4, Geeks, 8]
Element at 1st index is : Geeks
2. getFirst() : This method returns the first element in this list.
Declaration :
public E getFirst()
Return Value :
This method returns the first element in this list
Exceptions :
NoSuchElementException : if this list is empty
Java
import java.util.*;
public class LinkedListExcep1 {
public static void main(String[] args)
{
LinkedList<String> list = new LinkedList<String>();
list.add( "Geeks" );
list.add( "4" );
list.add( "Geeks" );
list.add( "8" );
System.out.println( "The element at index 7 is : "
+ list.get( 7 ));
}
}
|
Output :
The elements in List are : [Geeks, 4, Geeks, 8]
Element at 1st index is : Geeks
3. getLast() : This method returns the last element in this list.
Declaration :
public E getLast()
Return Value :
This method returns the last element in this list
Exceptions :
NoSuchElementException : if this list is empty
Java
import java.util.*;
public class LinkedListExcep2 {
public static void main(String[] args)
{
LinkedList<String> list = new LinkedList<String>();
System.out.println( "The first element of list is : "
+ list.getFirst());
}
}
|
Output:
The elements in List are : [Geeks, 4, Geeks, 8]
Element at last index is : 8
Exceptions
1. IndexOutOfBoundException
Output :
No Output
Runtime Error :
Exception in thread "main" java.lang.IndexOutOfBoundsException: Index: 7, Size: 4
at java.util.LinkedList.checkElementIndex(LinkedList.java:555)
at java.util.LinkedList.get(LinkedList.java:476)
at LinkedListExcep1.main(LinkedListExcep1.java:22)
2. NoSuchElementException
Java
import java.util.*;
public class LinkedListExcep2 {
public static void main(String[] args)
{
LinkedList<String> list = new LinkedList<String>();
System.out.println( "The first element of list is : "
+ list.getFirst());
}
}
|
Output :
No Output
Runtime Error :
Exception in thread "main" java.util.NoSuchElementException
at java.util.LinkedList.getFirst(LinkedList.java:244)
at LinkedListExcep2.main(LinkedListExcep2.java:15)
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