You better do rather than declare!
Functional programming is all about what you “do” rather than what you “are” or what something “is,” and that’s a cool way to code. Statements, like
a = a+b is the same as declaring with “is/are,” not what they do. So, in functional programming, the way could and should be
a => a+b, and by that, you got one less state: there is no state
a. You got
an as an input,
a + b as an output and that is it. You don’t need a state, or a “name” for your output as
a, you just need the output
a+b. In other words, you need one function with one expression for your output.