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 a for 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 a while 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 to while x >= 3:. This makes it easier to read and understand the purpose of the loop, and it eliminates the need of the break keyword.
Next Section - Lesson 03-11: for-else Loops