Vector firstElement() Method in Java
Last Updated :
24 May, 2023
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The java.util.vector.firstElement() method in Java is used to retrieve or fetch the first element of the Vector. It returns the element present at the 0th index of the vector
Syntax:
Vector.firstElement()
Parameters: The method does not take any parameter.
Return Value: The method returns the first element present in the Vector. Below programs illustrate the Java.util.Vector.firstElement() method:
Program 1:
Java
// Java code to illustrate firstElement()import java.util.*;public class VectorDemo { public static void main(String args[]) { // Creating an empty Vector Vector<String> vec_tor = new Vector<String>(); // Use add() method to add elements into the Vector vec_tor.add("Welcome"); vec_tor.add("To"); vec_tor.add("Geeks"); vec_tor.add("4"); vec_tor.add("Geeks"); // Displaying the Vector System.out.println("Vector: " + vec_tor); // Displaying the first element System.out.println("The first element is: " + vec_tor.firstElement()); }} |
Output:
Vector: [Welcome, To, Geeks, 4, Geeks] The first element is: Welcome
Program 2:
Java
// Java code to illustrate firstElement()import java.util.*;public class VectorDemo { public static void main(String args[]) { // Creating an empty Vector Vector<Integer> vec_tor = new Vector<Integer>(); // Use add() method to add elements into the Vector vec_tor.add(10); vec_tor.add(15); vec_tor.add(30); vec_tor.add(20); vec_tor.add(5); // Displaying the Vector System.out.println("Vector: " + vec_tor); // Displaying the first element System.out.println("The first element is: " + vec_tor.firstElement()); }} |
Output:
Vector: [10, 15, 30, 20, 5] The first element is: 10
Time complexity: O(1).
Auxiliary Space: O(n). // n is the size of the vector.
