The While Loop Else Clause
This lesson covers the while-loop-else
-clause, which is unique to Python. The else
-block is only executed if the while
-loop is exhausted. You don’t know what that means? Check out this lesson to find out! Furthermore, you can find two examples below, which you can copy-paste and run to get a sense of what’s happening.
n = 5
while n > 0:
n = n - 1
if n == 2:
break
print(n)
else:
print("Loop is finished")
n = 5
while n > 0:
n = n - 1
if n == 2:
continue
print(n)
else:
print("Loop is finished")
00:00
Now, there is one more thing we can add to our while
loop, and that is this else
statement. Now, this is actually unique to Python. Not a lot of other while
loops in other languages are going to have something like this.
00:13
But what it does is it gives us a way to execute a block of code right after the while
loop is exhausted. Now you could be thinking, “Well, why don’t I just do what I did before and add a statement to the end of my while
loop?” You can. However, there’s one weird thing about the else
statement and that is that it’s only going to happen if the while
loop is exhausted, meaning that if I were to use something like break
, it would not actually print. Let’s look at an example.
00:44
We’re going to use the same one that we just did, but for a minute we’re just going to go back to break
so we can see what happens.
00:57
I see that I did not actually print 'Loop is finished'
like I did before, and that’s because, remember, this else
statement is only going to execute if it is exhausted. So if I were to go back to continue
, this is actually going to continue on until that loop is exhausted, so it should print 'Loop is finished'
. Let’s see if that’s true.
01:22
There we go! Now, like I said, this is going to give you the same outcome as if you didn’t use this else
statement. The one thing to note is that if you do use a break
statement, that else
is not going to be executed. All right, so that’s going to pretty much wrap up the continue
and break
statements.
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byralph on Oct. 31, 2022
Hello, great course. Which tool do you use for presenting your code? Thank you.