Is assignment with "let" not against the idea of functional programming in Clojure

Question

Assignment should avoided in functional programming, but in clojure we often use let.

Is let just a way of being practical or is assignment not the same as using let? Should we not avoid assignment in functional programming?

Answer 1

It's fair to say that mutable state is generally against the core concepts of functional programming.

However, let merely binds a name to a value. If that value is itself immutable, there's no reason for it to be inconsistent with functional programming ideals.