What is the difference between Scala and Java?

Scala and Java are both object-oriented programming languages, but they have several key differences.

1. Static type vs dynamic type: Java is a statically typed language that requires specifying variable types during compilation, with type checking done at compile time. In contrast, Scala is a dynamically typed language that allows for type checking and inference at runtime.
2. Functional programming: Scala supports functional programming by providing features such as higher-order functions, anonymous functions, and closures. On the other hand, Java, although it can also use lambda expressions for functional programming, has relatively weaker support in this area.
3. Conciseness and expressiveness: Scala offers higher expressiveness compared to Java, allowing the same functionality to be achieved with less code. Scala provides some concise syntax sugars, such as collection operators and for expressions, making code easier to read and more concise.
4. Concurrent programming: Scala has built-in support for concurrent programming, offering features such as the Actor model and concurrent collections. In contrast, Java’s concurrent programming requires the use of low-level mechanisms like threads and locks.
5. Type inference: Scala has a stronger ability for type inference, automatically deducing the type of variables and expressions, reducing the need for redundant type declarations. In contrast, Java requires explicit declarations for variable and expression types.

In general, Scala is a more modern, expressive, and concise language that is well-suited for functional programming and concurrent programming. In contrast, Java is more stable and mature, making it better suited for large projects and enterprise applications.