beginner question - Printable Version

beginner question - Printable Version

+- Python Forum (https://python-forum.io)
+-- Forum: Python Coding (https://python-forum.io/forum-7.html)
+--- Forum: General Coding Help (https://python-forum.io/forum-8.html)
+--- Thread: beginner question (/thread-15371.html)

beginner question - Naito - Jan-15-2019

hi guys can you please help me understand the difference bteween these 2 codes?
my interpretation is def function has a loop in it (im not smart)

def func(x):
  res = 0
  for i in range(x):
     res += i
  return res

print(func(5))

output is 10

and

def func(x):
  for i in range(x):
     res = 0
     res += i
  return res

print(func(5))

output is 4
thanks for helping me

RE: beginner question - buran - Jan-15-2019

In the first snippet you make res==0 before the loop and then only add i in every iteration of the loop. So at the end it's the sum of all values in range(x)
In the second example you make res==0 in every iteration. So at the end res value is equal to the last value of i.

You can use http://www.pythontutor.com/visualize.html#mode=edit to visualise the execution of the code step by step for better understanding

RE: beginner question - Naito - Jan-15-2019

(Jan-15-2019, 07:41 AM)buran Wrote: In the first snippet you make res==0 before the loop and then only add i in every iteration of the loop. So at the end it's the sum of all values in range(x)
In the second example you make res==0 in every iteration. So at the end res value is equal to the last value of i.

You can use http://www.pythontutor.com/visualize.html#mode=edit to visualise the execution of the code step by step for better understanding

thank you it's much clear now