Question:

In a Java program, the following code snippet is provided:

public class ConstantsExample {
    public static void main(String[] args) {
        final int LENGTH = 5;
        int width = 7;

        int area = LENGTH * width;
        System.out.println("The area is: " + area);
    }
}

a) Identify the variable and constant used in the code snippet. b) Explain the difference between a variable and a constant. c) What happens if you try to reassign a value to the LENGTH variable inside the main method? Explain the reason behind the behavior.

Answer:

a) In the code snippet, the variable used is width and the constant used is LENGTH.

b) The main difference between a variable and a constant is that a variable can have its value changed during the execution of a program, while a constant has a fixed value that cannot be altered once it has been assigned.

c) If we try to reassign a value to the LENGTH variable inside the main method, we would get a compilation error. Constants, declared using the final keyword, are read-only and cannot be reassigned. Once a value is assigned to a constant, it cannot be changed throughout the program. This behavior ensures that the constant retains its intended value and prevents unintentional modifications. Therefore, any attempt to reassign a value to a constant would result in a compilation error.