Vector vs ArrayList in Java

 

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ArrayList vs. Vector in Java

Both ArrayList and Vector are part of the Java Collections Framework and implement the List interface. They are used to store dynamically resizable arrays of objects. However, there are some key differences between them:

1. Synchronization

• ArrayList: Not synchronized, meaning it is not thread-safe. Multiple threads can access an ArrayList simultaneously without any synchronization.
• Vector: Synchronized, meaning it is thread-safe. Only one thread can access a Vector at a time, which can be useful in multi-threaded environments but may lead to performance overhead12.

2. Performance

• ArrayList: Generally faster because it is not synchronized. Suitable for single-threaded applications.
• Vector: Slower due to synchronization. Suitable for multi-threaded applications where thread safety is required12.

3. Growth Rate

• ArrayList: Increases its size by 50% of the current array size when the number of elements exceeds its capacity.
• Vector: Doubles its size when the number of elements exceeds its capacity12.

4. Legacy

• ArrayList: Introduced in JDK 1.2 and is part of the Java Collections Framework.
• Vector: Considered a legacy class, introduced in JDK 1.0 but retrofitted to implement the List interface12.

5. Traversal

• ArrayList: Uses the Iterator interface for traversing elements.
• Vector: Can use both Iterator and Enumeration interfaces for traversing elements12.

Example of ArrayList

Java

import java.util.ArrayList;
import java.util.Iterator;

public class ArrayListExample {
    public static void main(String[] args) {
        ArrayList<String> arrayList = new ArrayList<>();
        arrayList.add("Apple");
        arrayList.add("Banana");
        arrayList.add("Orange");

        // Traversing elements using Iterator
        Iterator<String> iterator = arrayList.iterator();
        while (iterator.hasNext()) {
            System.out.println(iterator.next());
        }
    }
}

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

Example of Vector

Java

import java.util.Vector;
import java.util.Enumeration;

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

        // Traversing elements using Enumeration
        Enumeration<String> enumeration = vector.elements();
        while (enumeration.hasMoreElements()) {
            System.out.println(enumeration.nextElement());
        }
    }
}

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

When to Use Which?

• Use ArrayList: When you need a fast, non-synchronized list for single-threaded applications.
• Use Vector: When you need a thread-safe list for multi-threaded applications.

Would you like to dive deeper into any specific aspect of ArrayList or Vector?