Can you explain what it means to use the keyword 'final' for variables in Java?

In Java, the keyword final when declaring a variable means that after initialization, the value of this variable cannot be changed.

This means:

• For primitive types (int, boolean, etc.), the value is fixed and cannot be reassigned.
• For reference types (objects), the reference cannot be changed to point to another object, but the object itself can be mutable (if its methods allow).

Example:

final int x = 10;
x = 20; // Compilation error

final List<String> list = new ArrayList<>();
list.add("item"); // Allowed, the object is modified
list = new ArrayList<>(); // Error, cannot reassign the reference

Using final helps make the code more predictable and safe.