I have been mostly writing Object-oriented code in my day to day work and have little experience with functional programming.
In JavaScript/typescript code, we can definitely pass objects as parameters to functions. My question is whether passing objects to functions violates the functional programming paradigm as I am mixing object oriented code with functional style programming. (Even though The object passed into the function does not get mutated).
For example, if I have a function f(x,y) => z where x is an object that defines some interface. Object x makes a network call to access some resource which is used to compute z. We can say that such a function still adheres to the functional programming concept of it having no side effects and it being pure even though there is mixing of OO code in the function parameter ?
Hope my question was clear.
if I have a function
f(x,y) => zwherexis an object that defines some interface. Objectxmakes a network call to access some resource which is used to computez.
If x makes a network call and uses the result to compute z, then it's (by most definitions) non-deterministic (since it performs I/O) and thereby not a pure function. This further means that f is impure, too. I don't consider that FP. Rather, it's an attempt at Dependency Injection.
This doesn't mean, however, that you can't pass 'data structures' as parameters - they just have to be immutable or other pure functions.
If, instead, object x implemented an interface that defines a pure function (an algorithm, say), you can pass it as a parameter, use the pure function, and the function that uses the 'object' might still be pure.