Vector in java

 

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Vector in Java Collection

The Vector class in Java is part of the java.util package and implements the List interface. It is similar to ArrayList but with some differences, primarily related to synchronization.

Key Characteristics of Vector

1. Resizable Array: Like ArrayList, Vector implements a dynamic array that can grow or shrink as needed.
2. Synchronization: All methods in Vector are synchronized, making it thread-safe. This means that only one thread can access a Vector object at a time, which can be useful in multi-threaded environments but may lead to performance overhead.
3. Legacy Class: Vector is considered a legacy class, but it is fully compatible with the collections framework.

Creating a Vector

You can create a Vector in several ways:

Java

import java.util.Vector;

public class VectorExample {
    public static void main(String[] args) {
        // Default constructor
        Vector<Integer> vector1 = new Vector<>();

        // Specifying initial capacity
        Vector<Integer> vector2 = new Vector<>(10);

        // Specifying initial capacity and capacity increment
        Vector<Integer> vector3 = new Vector<>(10, 5);
    }
}

Adding Elements to a Vector

You can add elements to a Vector using the add method:

Java

Accessing Elements

You can access elements using the get method or an iterator:

Java

import java.util.Vector;
import java.util.Iterator;

public class AccessElements {
    public static void main(String[] args) {
        Vector<String> vector = new Vector<>();
        vector.add("Apple");
        vector.add("Banana");
        vector.add("Orange");

        // Using get method
        String element = vector.get(1);
        System.out.println("Element at index 1: " + element);

        // Using iterator
        Iterator<String> iterator = vector.iterator();
        System.out.print("Vector elements: ");
        while (iterator.hasNext()) {
            System.out.print(iterator.next() + " ");
        }
    }
}

AI-generated code. Review and use carefully. More info on FAQ.

Removing Elements

You can remove elements using the remove method:

Java

import java.util.Vector;

public class RemoveElements {
    public static void main(String[] args) {
        Vector<String> vector = new Vector<>();
        vector.add("Apple");
        vector.add("Banana");
        vector.add("Orange");

        vector.remove(1); // Removing element at index 1
        vector.remove("Orange"); // Removing specific element

        System.out.println("Vector after removal: " + vector);
    }
}

Example: Using Vector in a Real-World Scenario

Consider a scenario where you need to manage a list of students in a classroom. You can use a Vector to store and manipulate this list:

Java

import java.util.Vector;

class Student {
    private String name;
    private int rollNumber;

    public Student(String name, int rollNumber) {
        this.name = name;
        this.rollNumber = rollNumber;
    }

    @Override
    public String toString() {
        return "Student{name='" + name + "', rollNumber=" + rollNumber + "}";
    }
}

public class Classroom {
    public static void main(String[] args) {
        Vector<Student> students = new Vector<>();

        // Adding students
        students.add(new Student("Alice", 1));
        students.add(new Student("Bob", 2));
        students.add(new Student("Charlie", 3));

        // Displaying students
        System.out.println("Students in the classroom:");
        for (Student student : students) {
            System.out.println(student);
        }

        // Removing a student
        students.remove(1); // Removing the student at index 1

        // Displaying students after removal
        System.out.println("Students after removal:");
        for (Student student : students) {
            System.out.println(student);
        }
    }
}

ArrayIndexOutOfBound example:
Vector<Integer> vec = new Vector<Integer>();
vec.add(0,11);
vec.add(1,22);
vec.add(3, 33); //THIS WILL GIVE ARRAYINDEXOUTOFBOUNDEXCEPTION

vec.add(1,44); //This will move the existing element at 1th position to the next position and this new element will be added to the first index.