Does Java 10 Introduce a `val` Keyword for Final Variables?

Does Java 10 provide a `val` keyword similar to Scala for defining final variables?

Java 10 introduces the `var` keyword for local variable type inference but does not provide a `val` keyword for final variables. This decision stems from Java’s design principles and its long-standing history of handling variable immutability differently than some other languages like Scala.

public class Main {
    public static void main(String[] args) {
        final String message = "Hello, world!"; // message is final
        // message = "abc"; // This would cause a compilation error
    }
}

Causes

• Java's existing design emphasizes explicit declaration of variable mutability through keywords such as `final` rather than adopting shorthand keywords like `val` for immutability.
• The language aims to maintain backward compatibility and reduce complexity by minimizing the introduction of new keywords that might confuse developers familiar with traditional Java.

Solutions

• To declare a final variable in Java, you can still use the `final` keyword. This maintains clarity while ensuring that the variable cannot be reassigned.
• For example, instead of using a hypothetical `val`, you can use: `final String message = "Hello, world!";`.

Mistake: Misunderstanding the role of `final` versus `var` in Java.

Solution: Remember that `final` is used to declare constants that cannot be reassigned, while `var` is for type inference with local variables.

Mistake: Confusing the concept of immutability with the `var` keyword.

Solution: Understand that `var` does not imply immutability; the variable declared with `var` can still be reassigned unless declared as `final`.