What is mutable data in functional programming?

What is mutable data in functional programming?

In functional programming, mutable data refers to data that can be changed after it has been created. This contrasts with immutable data, which cannot be altered once it's set.

Why is immutability preferred in functional programming?

Immutability is preferred because it helps avoid side effects, making programs easier to reason about, test, and debug.

Can you give an example of mutable vs immutable data?

Sure! In JavaScript, an array is mutable; you can change its elements. A string, however, is immutable; any modification creates a new string.

How does mutable data affect performance?

Mutable data can lead to performance improvements in certain scenarios, as it allows in-place updates. However, it can also introduce complexity and bugs due to unintended side effects.