Java Deque getFirst() Method with Examples

by Online Tutorials Library July 22, 2022

Java Deque getFirst() Method

The getFirst() method of Java Deque Interface retrieves but does not remove the first element of the given deque. The above method differs from peekFirst only in one way that it throws an exception if the deque is empty.

Syntax:

Parameter:

Return:

The above method returns the head of the deque.

Example 1

  import java.util.ArrayDeque;  import java.util.Deque;  public class JavaDequegetFirstExample1 {     public static void main(String[] args) {  Deque<Float> deque = new ArrayDeque<>();  System.out.println(“The list of the elements is given as : “);  deque.add(44f);  deque.add(66f);  deque.add(11f);  deque.add(99f);  System.out.println(deque);  Float val = deque.getFirst();    System.out.println(“The final result of the deque is given as : “+val);  }  }  

Test it Now

Output:

The list of the elements is given as :   [44.0, 66.0, 11.0, 99.0]  The final result of the deque is given as : 44.0

Example 2

  import java.util.ArrayDeque;  import java.util.Deque;  public class JavaDequegetFirstExample2 {     public static void main(String[] args) {  Deque<Character> deque = new ArrayDeque<>();  System.out.println(“The list of the elements is given as : “);  deque.add(‘k’);  deque.add(‘p’);  deque.add(‘m’);  deque.add(‘t’);  System.out.println(deque);  Character val = deque.getFirst();    System.out.println(“The final result of the deque is given as : “+val);  }  }  

Test it Now

Output:

The list of the elements is given as :   [k, p, m, t]  The final result of the deque is given as : k

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