Java Deque offerFirst() Method with Examples

by Online Tutorials Library July 22, 2022

Java Deque offerFirst() Method

The offerFirst() method of Java Deque Interface is used to insert the given element in the front of the deque unless and until it violates the capacity restrictions. While using a capacity restricted deque , the above method is used for addFirst(E) method.

Syntax:

Parameter:

The above method requires only one parameter :

The element ‘e’ that needs to be added.

Return:

The above method is used to return a Boolean value, i.e., true if the element is added to the queue. Otherwise, returns false.

Throw:

ClassCastException– If the class for the given element avoids it from being added to the deque.

NullPointerException– If the specified element is a null and the given deque does not allow the null elements.

IlleagalArgumentException– If some properties of the specified element prevents it from being added to the deque.

Example 1

  import java.util.ArrayDeque;  import java.util.Deque;  public class JavaDequeofferFirstExample1 {     public static void main(String[] args) {  Deque<Character> deque = new ArrayDeque<>();    deque.offerFirst(‘J’);    deque.offerFirst(‘A’);    deque.offerFirst(‘V’);    deque.offerFirst(‘A’);  System.out.println(“The final deque is given as : “);      for (Character character : deque) {  System.out.println(character);      }       }    }   

Test it Now

Output:

The final deque is given as :   A  V  A  J

Example 2

  import java.util.ArrayDeque;  import java.util.Deque;  public class JavaDequeofferFirstExample2 {     public static void main(String[] args) {  Deque<String> deque = new ArrayDeque<>();    deque.offerFirst(“Java”);    deque.offerFirst(“is”);    deque.offerFirst(“a”);    deque.offerFirst(“secured”);    deque.offerFirst(“language”);  System.out.println(“The final deque is given as : “);      for (String string : deque) {  System.out.println(string);     }       }    }    

Test it Now

Output:

The final deque is given as :   language  secured  a  is  Java

Example 3

  import java.util.ArrayDeque;  import java.util.Deque;  public class JavaDequeofferFirstExample3 {     public static void main(String[] args) {  Deque<Integer> deque = new ArrayDeque<>();    deque.offerFirst(1);    deque.offerFirst(2);    deque.offerFirst(3);    deque.offerFirst(4);    deque.offerFirst(5);  System.out.println(“The final deque is given as : “);      for (Integer integer : deque) {  System.out.println(integer);       }       }    }     

Test it Now

Output:

The final deque is given as :   5  4  3  2  1

Next TopicJava Deque

add()addAll()addfirst()addlast()contains()descendingiterator()element()getfirst()getlast()iterator java deque java tutorial methods offer()offerfirst()offerlast()peek()peekfirst()peeklast()poll()pollfirst()polllast()

Java Deque offerFirst() Method with Examples

Java Deque offerFirst() Method

Syntax:

Parameter:

Return:

Throw:

Example 1

Example 2

Example 3

Java ConcurrentHashMap putIfAbsent() Method

Java Abstract Keyword

You may also like