Explanation

Question

Can someone explain why the code below outputs '6'?

def fun(x):
res = 0

for i in range(x):
res += i

return res

print(func(4))

Answer 1

It is summing up. On the first loop, it will do res (that is 0) + i (that will also be zero) and the result will be zero. On the second loop, it will be 0 + 1, so res is now 1. On the third loop, it will be 1 + 2, and res will be 3. Finally, the forth loop does 3 + 3, and that is why res returns as 6.

If you want to count the loops instead of summing them up, you should write "res += 1" instead of "res += i".

Answer 2

There's something wrong with your indentation. In its current format the code won't run

range(x) contains all numbers from 0 to x-1. The sum of all numbers from 0 to 3 is 6

Answer 3

Understood. Thank you