Avoid These Java Collections Mistakes and Follow Best Practices

Java Collections Framework is powerful, but many developers unknowingly make mistakes that can lead to memory leaks, poor performance, and unexpected behavior. 😱

In this article, we will explore the top 10 mistakes developers make when using Java Collections and how to fix them with best practices. Let’s dive in! 🚀

Avoid These Java Collections Mistakes and Follow Best Practices

🔴 1️⃣ Using the Wrong Collection Type

Mistake: Choosing the wrong collection type can reduce performance or cause unexpected behavior.

❌ Bad Practice: Using ArrayList Instead of LinkedList for Frequent Insertions

List<Integer> list = new ArrayList<>();
for (int i = 0; i < 100000; i++) {
    list.add(0, i); // ❌ Inefficient! Shifts all elements on each insert
}

👉 Issue: ArrayList is bad for frequent insertions because it shifts all elements, leading to O(n) complexity.

✅ Best Practice: Use LinkedList for Frequent Insertions

List<Integer> list = new LinkedList<>();
for (int i = 0; i < 100000; i++) {
    list.add(0, i); // ✅ Efficient! O(1) insertions at the head
}