Java Vector firstElement()

Java Vector [Java Vector] Java Vector

firstElement() Java Vector (Vector) java.util.Vector Java 

public E firstElement()

  • ( 0 )
  • NoSuchElementException

1.

firstElement() O(1)

2.

Vector firstElement()

3.

NoSuchElementException

firstElement()

import java.util.Vector;

public class VectorFirstElementExample {
    public static void main(String[] args) {
        // Vector
        Vector<String> fruits = new Vector<>();
        fruits.add("Apple");
        fruits.add("Banana");
        fruits.add("Orange");
       
        //
        String firstFruit = fruits.firstElement();
        System.out.println(": " + firstFruit);
       
        //
        Vector<Integer> numbers = new Vector<>();
        if (!numbers.isEmpty()) {
            System.out.println(": " + numbers.firstElement());
        } else {
            System.out.println("Vector ");
        }
    }
}

: Apple
Vector

1.

firstElement() NoSuchElementException

2.

Java 5 Vector

3.

ArrayList get(0)

1.firstElement()vs get(0)

  • firstElement()Vector
  • get(0)List
  • firstElement()

2.firstElement()vs elementAt(0)

  • firstElement()elementAt(0)Vector
  • firstElement()

firstElement()

  1. Vector

Vector firstElement() Java ArrayList Vector

Java Vector [Java Vector] Java Vector