find-average-numbers-range()

Step 1: Declaring the function

Start by declaring a function named findAverageNumbersRange. This function will take two parameters - the starting number and the ending number of the range for which you want to find the average. Make sure to specify the data types of these parameters as Int.

func findAverageNumbersRange(start: Int, end: Int) {
// function body will go here
}

Step 2: Checking the validity of the range

Inside the function body, add a condition to check if the starting number is less than or equal to the ending number. If this is not the case, return nil. This ensures that the function handles incorrect input appropriately.

if start > end {
return nil
}

Step 3: Calculating the total and count

Next, initiate two variables - one for storing the total sum of all the numbers and the other for storing the count of numbers in the given range. Using a for-in loop, iterate over the range from the start to end number. On each iteration, add the current number to the total and increment the count by 1.

var total = 0
var count = 0

for number in start...end {
total += number
count += 1
}

Step 4: Calculating the average

After obtaining the total and count, calculate the average by dividing the total by the count. Make sure to convert the count to a Double before performing the division to get a floating-point result.

let average = Double(total) / Double(count)

Step 5: Returning the result

Finally, return the calculated average from the function.

return average

Putting it all together, here's the complete function implementation:

func findAverageNumbersRange(start: Int, end: Int) -> Double? {
if start > end {
return nil
}

var total = 0
var count = 0

for number in start...end {
total += number
count += 1
}

let average = Double(total) / Double(count)

return average
}

This function calculates the average of all the numbers in the specified range, returning nil if the range is invalid.