Are function arguments condtants or variable ?

[sanjayjain159]

Typically in a programming language, the function arguments are local variables. But as far as a noobie like me knows Janet treats function arguments a b c declared as in, (defn f [a b c] ...) as constants. How to get them as local variables whose value can be changed for example with set?

[bakpakin]

You cannot do that. I believe you are referring to "inout" parameters from other languages?

[avitkauskas]

But what about passing a mutable variable as parameter?
I tried this in REPL:

(def tab @{})
(defn fun [t] (put t :k "v"))
(fun tab)
(pp tab)
=> @{:k "v"}

Feels like "inout"..

[bakpakin]

Yes, this is the only way to do this. Function parameters are equivalent to bindings made with 'def'.