Using conditional statements in while loop

Question

I was under the impression that adding the following if statement in my while loop makes python pick only the odd values of i that are smaller than 7 and sums them. However, this is not the case.

Here's my code:

i = 0

sum = 0

while i < 7:

    if (i % 2) == 1:

        sum += i

        i += 1

I expect sum to be 9 but an infinite loop occurs, causing the sum to be infinite.

I can't seem to understand how. Any help is appreciated. Thanks in advance!

You only increment `i` inside the `if`, so if the condition is not meant, `i` stays the same forever — Adam.Er8, Jun 25 '19 at 11:56

score 1 · Answer 1 · answered Jun 25 '19 at 11:57

1

You only increment i inside the if, so if the condition is not meant, i stays the same forever

i = 0

sum = 0

while i < 7:

    if (i % 2) == 1:

        sum += i

    i += 1

print(sum)

Output:

9

answered Jun 25 '19 at 11:57

Adam.Er8

12,675
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score 0 · Answer 2 · answered Jun 25 '19 at 11:58

As you keep conditioning i % 2, but if it doesn't go through, the i never changes, it will always exit the if statement, to solve it:

i = 0

sum = 0

while i < 7:

    if (i % 2) == 1:

        sum += i

    i += 1

print(sum)

You have to unindent by 4 spaces your i += 1 line.

score 0 · Answer 3 · answered Jun 25 '19 at 12:12

0

For similar cases it is better to use for loop than while loop. Especially if you have long loops. link

sum = 0
for i in range(7):
    if (i % 2) == 1:
        sum += i

answered Jun 25 '19 at 12:12

Robot Mind

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Using conditional statements in while loop

3 Answers3