I'm learning Python. My goal is to print out 1 through 5, skipping 3, using a while loop, if statement, and keyword continue. My code below prints out just 1 2, and not 1 2 4 5.

i = 1
while i <= 5:
    if i == 3:
        continue
    print(i)
    i  = 1

1. Why does this loop stop when i == 3, rather than skipping 3 and continuing with i = 4 and i = 5?
2. How would you correct this code so that it prints 1 2 4 5 (continuing/skipping 3)?

CodePudding user response：

To fix this you can do it like this, print the value when it is not three and then you don't even need to use continue:

i = 1
while i <= 5:
    if i != 3:
        print(i)
    i  = 1

However, a faster and easier solution would be this:

for i in range(1, 5   1):
    if i != 3:
        print(i)

Or in the for loop case it would be possible to use continue because the for loop will continue to the next element:

for i in range(1, 5   1):
    if i == 3:
        continue
    print(i)

And just because, but you can also use a short (linewise) (and fast too) solution like this one:

print('\n'.join(str(i) for i in range(1, 5   1) if i != 3))

CodePudding user response：

Once you reach 3 the program will never increase i anymore and will loop forever

You could increment before the test:

i = 0
while i <= 5:
    i  = 1
    if i == 3:
        continue
    print(i)

CodePudding user response：

When you call continue, the increment will be skipped and i will be stuck at 3 forever

CodePudding user response：

You're stuck in an infinite loop. When you continue, you never increment i, so it stays 3 forever.

CodePudding user response：

Because continue makes you not fulfill the rest of your code. Therefore, you just have an infinite loop. You can see that if you run

i = 1
while i <= 5:
    if i == 3:
        print(i)
        continue
    print(i)
    i  = 1

If you want to do this in this method, you can just increment i before your continue, i.e.

i = 1
while i <= 5:
    if i == 3:
        i =1
        continue
    print(i)
    i  = 1

CodePudding user response：

Your loop doesn't stop once you hit 3, rather it continues indefinitely as you always skip incrementing i once the value of i reaches 3.

You need to do something in your if block before you continue to ensure you don't get stuck in an infinite loop.

CodePudding user response：

You have an infinite loop, when you reach i == 3, you want to skip it, and you do it by using continue. continue means going back to the while condition and evaluating it.

Because you didn't increment i, the statement will always be true (always less than 5), but because you didn't change i, the if condition will also be always true. And your code loops inifintely.

You need to change the value of i before continue in the if block.