What are the reasons for using wrapper classes?

• Working with primitives as objects: Wrapper classes allow calling methods characteristic of objects (e.g., .toString(), .equals()) on primitive types.
• Usage in collections: Collections in Java (e.g., ArrayList, HashMap) can only store objects, not primitive types. Wrapper classes enable including primitives in collections.
• Null values: Primitive types cannot have a null value, whereas wrapper classes can. This is useful when representing the absence of a value.
• Autoboxing and unboxing: Autoboxing and unboxing simplify conversion between primitive types and their wrapper classes.

// Example of autoboxing and unboxing
Integer num = 10; // autoboxing: int -> Integer
int value = num; // unboxing: Integer -> int

• Thread safety: Some wrapper classes are immutable, which promotes thread safety since their state cannot be changed after creation.
• Constants: Wrapper classes provide useful constants related to the type (e.g., Integer.MAX_VALUE, Double.NaN).