for range()

Question

can anyone help with explanation. why answer is 8?

for i in range (5):
i=i+i
print (i)

Answer 1

and what about this?

j=0
for z in range (100):
j=j+j
print (j)
output:0

I can't just see difference between this and above example. Plus in cases j=j+1, j=j+2, etc answers respectively are 100, 200 etc. why?

Answer 2

anyway thanks, I will review again.

Answer 3

i is 0
i is 1
i is 1+1
i is 2+2
i is 3+3
i is 4+4
i is 8!
Note:
The range() function will not reach 5! It stops one before.
This is very important!!

Answer 4

sorry I edited my post. look again please

Answer 5

b is 0. B is never changed.
You do
for j!!
do for b in range...

Answer 6

That doesn't output 0.

Answer 7

J will either be 198 or 398 (if you use range(100) or range(200)

Answer 8

ok