What is the performance difference between using primitive data types and their object wrappers?

Using primitive data types in Java is generally faster and more memory-efficient than their wrapper objects (e.g., int vs Integer).

Reasons:

• Primitives are stored directly in the stack or in object fields, requiring no additional memory for an object.
• Wrappers are full objects created on the heap, requiring time for memory allocation and garbage collection.
• Autoboxing and unboxing add overhead when converting between primitives and wrappers.

Example:

int a = 5; // primitive
Integer b = 5; // wrapper object

// When performing calculations with Integer, unboxing occurs:
int c = b + 10; // b is unboxed to int

In performance-critical areas, it is preferable to use primitives to avoid unnecessary overhead.