Constants in Java

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A constant is a variable whose value cannot be changed once assigned.
In Java, constants are created using the final keyword.

final Keyword

When a variable is declared as final, its value cannot be modified after initialization.
Example:
Once MAX_USERS is assigned 100, it cannot be changed.

final with Different Data Types

Constants are useful when values should never change, such as configuration values.

Naming Convention for Constants

By convention, constant names:
  • Are written in uppercase
  • Use underscore to separate words
Correct:
Not recommended:
Using uppercase makes constants easily identifiable in large programs.

Final with Objects

When final is used with objects, the reference cannot change, but object data can still be modified.
The reference sb cannot point to another object, but its content can change.