🎯 1. What Are Wrapper Classes?

Wrapper classes convert primitive data types into objects.

Primitive → Object

int → Integer

double → Double

char → Character

boolean → Boolean

Why?

Because many Java APIs work only with objects, not primitives.

Examples:

Collections, Generics, Streams, HashMap, ArrayList

⭐ 2. Why Wrapper Classes Exist?

✔ Allow primitives in collections

✔ Provide utility methods

✔ Enable null values (primitives can’t)

✔ Needed for OOP + frameworks

✔ Works with Generics (List<Integer> not List<int>)