Lesson 03-10: The break
Keyword¶
Learning Target: I can use the break keyword to end a loop early.
What does break
do?¶
On occasion, there comes a time when you want to stop your loop right away. That’s what the break keyword
does. Take the following as an example:
This also works for for
loops as well:
The break
keyword only quits out of the “innermost” loop. This means that if you have a loop inside of a loop (also covered later), using break
will only quit out of the most recently-used loop.
When to use break
?¶
break
is not a keyword you should be using often in your programs. In general, you want to follow the following guidelines when you are thinking about using break
:
Use
break
to exit afor
loop early - because there is no other way to do this.- This is nice because it allows us to provide two ways for a for loop to end - either it loops through everything, or it breaks due to some condition.
In general, you should avoid using
break
in awhile
loop, because it is an indicator that you could just write a better condition for the loop.- Take the first example above as an example of BAD
break
usage. Instead of using a conditional to break out of the loop, you could’ve rewritten line 3 towhile x >= 3:
. This makes it easier to read and understand the purpose of the loop, and it eliminates the need of thebreak
keyword.
- Take the first example above as an example of BAD
for
-else
Loops