How can I write a Ruby function that can calculate the average of an array? If the array doesn't have any elements, the result should be 0. I should use a loop for the implementation. I started like this, but I'm not quite sure how to use the loop.
a = [1, 2, 3, 4, 5, 6]
def average(a)
sum = 0.0
result = 0.0
if array.length > 0 then
array.each do |item|
sum += item
end
result = sum / array.length
end
return result.to_f
end
def average(arr, precision=0)
return 0 if arr.empty?
arr.sum.fdiv(arr.size).round(precision)
end
arr = [1,2,3,7]
average(arr) #=> 3
average(arr,2) #=> 3.25
Rather than using Integer#fdiv you could write
(arr.sum.to_f/arr.size).round(precision)
I suppose we can also write it simply as below
a = [1, 2, 3, 4, 5, 6]
def average(arr=[])
sum = 0.0
i=0
while(i < arr.length) do
sum += arr[i].to_f
i += 1
end
return ((i==0) ? 0 : (sum / i))
end
We can loop and calculate sum this way. Afterwards for average we took value of i which will be retained value after loop and make conditional operator for returning result.
Its simple solution, I have not tested it though so can have mistakes. You can try on your side. Hope This helps !!
You can write this:
def average(values)
total = 0.0
values.each do |i|
total += i
end
return total / values.length()
end
If you want to use a loop, you can do it this way:
def average(values=[])
total = 0.0
for i in values
total += i
end
return total / values.length()
end
If a non-empty array is passed, it will return the average of the values. If an empty array is passed, it will return 0.0.
You can test it like this:
puts average([1, 2, 3, 4, 5]) #=> "3"
puts average([]) #=> "0"
"3" nor "0"
for / in is simply syntactic sugar for each (with slightly different semantics for variable binding), so your two examples are more or less the same. The only actual loop construct Ruby has, is the while loop.3.0 and NaNdef average(a)
if a.empty?
0
else
sum = a.inject(0.0){|x, sum| sum += x}
sum / a.size.to_f
end
end
