Java Constants
Java Constants (final)
In Java Constants (final) is a variable whose value cannot be changed once it is assigned.
To declare a constant, you use the final keyword.
Basic Example
If you try to change the value later:
Why Use Constants?
To store fixed values that should not be changed in the program.
Improves readability and avoids accidental modification.
Recommended Naming Convention
Constant names are written in UPPERCASE letters, often with underscores:
Constant with static
Often constants are declared as both:
static→ belongs to the class, not objectsfinal→ value can’t change
Example:
Final with Strings and Objects
final prevents reassignment — but not modification of internal content (for objects).
Example:
Final with Methods and Classes (Advanced — For later)
| Keyword | Meaning |
|---|---|
final variable | Value cannot be changed |
final method | Method cannot be overridden |
final class | Class cannot be inherited |
Example:
Full Example Program
Summary
| Feature | Description |
|---|---|
| Keyword | final |
| Can change value? | No |
| Naming convention | UPPERCASE |
| Used for | Fixed values, security, readability |
