Swift- 'For' Loop not adding variable to total result - ios

Question

I am trying to create a function in Playground using Swift where a calculation is made several times, and then added to the total sum of calculations until the loop is over. Everything seems to be working, except that when I try to sum the every calculation to the last total, it just gives me the value of the calculation. Here is my code:
func Calc(diff: String, hsh: String, sperunit: Float, rate: Float, n: Int16, p: Float, length: Int16) -> Float {
//Divisions per Year
let a: Int16 = length/n
let rem = length - (a*n)
let spl = Calc(diff, hsh: hash, sperunit: sperunit, rate: rate)
for var i = 0; i < Int(a) ; i++ { //also tried for i in i..<a
var result: Float = 0
let h = (spl * Float(n) / pow (p,Float(i))) //This gives me a correct result
result += h //This gives me the same result from h
finalResult = result
}
finalResult = finalResult + (Float(rem) * spl / pow (p,Float(a))) //This line is meant to get the result variable out of the loop and do an extra calculation outside of the loop
print(finalResult)
return finalResult
}
Am I doing something wrong?

Answer 1

Currently your variable result is scoped to the loop and does not exist outside of it. Additionally every run of the loop creates a new result variable, initialized with 0.
What you have to do is move the line var result: Float = 0 in front of the for loop:
var result: Float = 0
for var i = 0; i < Int(a) ; i++ {
let h = (spl * Float(n) / pow (p,Float(i)))
result += h
finalResult = result
}
Additionally you can remove the repeated assignment of finalResult = result and just do it once after the loop is over.
You can probably remove the finalResult completely. Just write
var result: Float = 0
for var i = 0; i < Int(a) ; i++ {
let h = (spl * Float(n) / pow (p,Float(i)))
result += h
}
result += (Float(rem) * spl / pow (p,Float(a)))
print(result)
return result