In functional programming, looping is performed by recursive functions. In F#, to make a function recursive, we need to use the rec keyword. By default, functions are not recursive in F#, we have to rectify this explicitly using the rec keyword. Let's take an example:
let rec summation x = if x = 0 then 0 else x + summation(x-1)printfn "The summation of first 10 integers is- %A" (summation 10)
In this code, we used the keyword rec for the recursion function and if the value passed is 0 , the sum would be 0; otherewise it will add x + summation(x-1), like 1+0 then 2+1 and so on. We should take care with recursion because it can consume memory heavily.
