What is the difference between mutable and immutable data in functional programming?

What is the difference between mutable and immutable data in functional programming?

In functional programming, mutable data can be changed after it's created, while immutable data cannot be altered once it's set.

Can you give me an example of mutable and immutable data?

Sure! An array in JavaScript is mutable because you can change its elements. A string, however, is immutable; once created, it cannot be changed.

Why is immutability preferred in functional programming?

Immutability helps avoid side effects, making code easier to understand, test, and debug. It also enables safer concurrent programming.

Are there any downsides to using immutable data?

Yes, using immutable data can lead to performance overhead due to the need to create new copies of data instead of modifying existing ones.