Wrapper Classes in Java: A Simple Guide for Beginners

Learn what wrapper classes are in Java, why they’re important, and how to use them effectively. Includes code examples and real-world use cases.

What Are Wrapper Classes in Java?

In Java, wrapper classes are used to convert primitive types into objects.

Java is an object-oriented language, but primitive types like int, double, char are not objects.

So Java provides wrapper classes for each primitive data type to help you use them like objects.

Why Are Wrapper Classes Useful?

1️⃣ To Use Primitives in Collections

Collections like ArrayList, HashMap only store objects, not primitives.

List<Integer> numbers = new ArrayList<>();
numbers.add(10); // int is converted to Integer automatically

2️⃣ Autoboxing and Unboxing

Java automatically converts between primitive types and wrapper classes:

• Autoboxing → Primitive to Object
• Unboxing → Object to Primitive

int a = 5;
Integer obj = a…