What is mutability in functional programming?

What is mutability in functional programming?

In functional programming, mutability refers to the ability to change the state or value of an object after it has been created. Unlike imperative programming, where variables can be modified, functional programming emphasizes immutability, meaning once a data structure is created, it cannot be changed.

Why is immutability preferred in functional programming?

Immutability is preferred because it leads to safer code, easier reasoning about program behavior, and better support for concurrent programming. Since data cannot change, you avoid side effects that can lead to bugs.

Can you give an example of mutable vs immutable data structures?

Sure! In Python, a list is mutable, meaning you can change its contents. For example, you can append or remove items. In contrast, a tuple is immutable; once created, you cannot change its elements.

How does immutability affect performance?

Immutability can have performance implications, as creating new instances of data structures can be more resource-intensive than modifying existing ones. However, many functional programming languages optimize this through techniques like structural sharing.

What are some languages that support functional programming?

Languages that support functional programming include Haskell, Scala, Clojure, and even JavaScript, which has functional programming features.