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Roland O'Donnell
Roland O'Donnell
5,667 Points

Learning Swft and have a question about code which i don't understand

func average(numbers: Int...) -> Int  {
    var total = 0
    for ave in numbers {
        total += ave
    return total / numbers.count

i just want make sure i know whats exactly going on here!

//Why can't i just have 
for total in numbers  
//and just  leave the 
total += ave 
out of the code??

sorry if i sound stupid..im a beginner

1 Answer

Hi Roland,

The function receives numbers as a parameter. That can hold multiple integers as in your example, it will hold 23, 263 and 848. The purpose of the function is to return the average of those numbers.

The func's purpose is to receive a list of numbers and return the average of those numbers. To form an average, you add up all your numbers and divide by the number of them, right?

So, to add them up, we're iterating through the list of numbers. At each iteration, the number from numbers is held in the local variable, ave. At each pass, ave is added to total which is set to zero at the start. So, the first loop, ave will hold 23 which gets added to total (which is currently zero). Next pass and ave holds 263 - this is added to total and so on, one more time with ave holding the last number, 848. Then total holds 23 + 263 + 848 = 1,134.

Once we have finished iterating over the numbers, the for loop ends. We then divide the sum of all the numbers, contained in total by the number of elements passed in, numbers.count and return this.

Make sense?


Roland O'Donnell
Roland O'Donnell
5,667 Points

oh i get it now.. works its way down 1 step 2 step 3 step then back to the top. total += ave is essentially storing the info to the total. thanks for your answer..appreciated.

Yep - that's right. The variable ave is used to temporarily store each individual number held in numbers and total holds a rolling sum of those values.