Get a skill gap analysis, personalised roadmap, and AI-powered resume optimisation.
Introduction
The break statement is an important feature in Python that helps you to control the flow of your code. It implements a crucial function: it terminates the loop it is part of, stops the execution of the loop immediately, and transfers the flow of control to the next line following the loop, which gives you more flexibility and power in your programs.
In this article, we'll discuss what the break statement is and how to use it with different types of loops, along with examples.
Python break Statement
The break statement in Python is used to exit out of a loop prematurely. When Python encounters a break statement inside a loop, it immediately stops executing that loop and moves on to the next line of code outside the loop. This is useful when you want to stop a loop based on a certain condition rather than waiting for the loop to finish iterating.
For example, let's say you have a loop that's searching through a list of numbers to find a specific value. Once the value is found, you should break out of the loop since there's no need to keep searching. The break statement allows you to do this.
For example:
numbers = [1, 2, 3, 4, 5]
search_value = 3
for num in numbers:
if num == search_value:
print(f"Found the number {search_value}!")
break
In this code, we loop through the "numbers" list until we find the "search_value" of 3. When that value is found, we print a message & then use "break" to exit the loop early.
Syntax of break Statement
The syntax for the break statement in Python is very simple. You just write the keyword "break" on a line by itself within a loop. This is how it looks like:
for item in sequence:
if condition:
break
Or in a while loop:
while condition:
if another_condition:
break
When Python reaches the break statement, it immediately exits the loop it's currently in. Any remaining iterations of the loop are skipped, and the program continues with the next line of code after the loop.
It's important to note that the break statement only breaks out of the innermost loop it's in. If you have nested loops & use a break in an inner loop, it will only exit that inner loop, not any outer loops.
For example:
for i in range(5):
for j in range(5):
if j == 3:
break
print(i, j)
print("---")
You can also try this code with Online Python Compiler
Notice how the break statement only causes the inner j loop to exit early, not the outer i loop.
Flow Diagram of Break Statement
To help visualize how the break statement works, let's look at a flow diagram. Flow diagrams show the different paths a program can take based on certain conditions.
As you can see, the loop starts & performs some operation. Then it checks a condition. If that condition is satisfied, the break statement is executed which causes the loop to end early. If the condition is not satisfied, the loop continues to the next iteration.
break Statement with for loop:
The break statement is commonly used with for loops in Python. When break is executed inside a for loop, it immediately terminates the loop and transfers control to the next statement after the loop.
For example:
fruits = ["apple", "banana", "cherry", "date"]
for fruit in fruits:
if fruit == "cherry":
break
print(fruit)
print("Done")
You can also try this code with Online Python Compiler
In this example, we have a list of fruits that we iterate over using a for loop. Inside the loop, we check if the current fruit is "cherry". If it is, we execute the break statement, which causes the loop to terminate early. So, only "apple" & "banana" get printed before the loop ends.
After the loop, the print("Done") statement is executed, as it comes after the loop in the code.
Note: The break statement is very useful when you want to stop a for loop based on a certain condition, like finding a specific item in a list, reaching a certain number in a range, or any other condition you specify.
break Statement with while loop
The break statement is also frequently used with while loops in Python. When break is executed inside a while loop, it immediately terminates the loop, regardless of the condition, and transfers control to the next statement after the loop.
For example:
count = 0
while True:
print(count)
count += 1
if count >= 5:
break
print("Done")
You can also try this code with Online Python Compiler
In this example, we have a while loop that runs indefinitely because its condition is always True. Inside the loop, we print the current value of count, increment count by 1, and then check if count is greater than or equal to 5. If it is, we execute the break statement, which causes the loop to terminate.
So, this loop will print the numbers 0 through 4, and then the break statement will be executed, causing the loop to end. After the loop, the print("Done") statement is executed.
Note: The break statement is useful when you want to stop a while loop based on a certain condition that may occur inside the loop, rather than in the loop's condition itself.
Break Statement with Nested Loops
The break statement in Python can also be used with nested loops, which are loops inside other loops. When break is used in a nested loop, it only terminates the innermost loop it's in, not any outer loops.
For example:
for i in range(3):
for j in range(3):
if i == 1 and j == 1:
break
print(i, j)
print("---")
You can also try this code with Online Python Compiler
In this example, we have an outer for loop that iterates over the numbers 0 to 2 (using range(3)). Inside that loop, we have another for loop that also iterates over the numbers 0 to 2.
Inside the inner loop, we check if i and j are both equal to 1. If they are, we execute the break statement. This causes the inner loop to terminate early, but the outer loop continues.
So, the output shows that for i=0, all values of j are printed. For i=1, only j=0 is printed before the break statement is executed. For i=2, all values of j are printed again because the break statement only affected the inner loop when i was 1.
Frequently Asked Questions
What happens if I use break outside of a loop?
If you use the break statement outside of a loop, you'll get a SyntaxError because break is only valid inside loops.
Can I use break in a function?
Yes, you can use break inside a function as long as it's used within a loop in that function. The break will only affect the loop it's directly inside.
Is there a way to break out of multiple nested loops at once?
No, the break statement only breaks out of the innermost loop it's in. If you need to break out of multiple loops, you can use a flag variable or restructure your code to avoid deep nesting.
Conclusion
In this article, we've learned about the break statement in Python and how it's used to control the flow of loops. We've seen the syntax of break, visualized its operation with a flow diagram, and explained how it works with for loops, while loops, and nested loops. The break statement is a powerful tool that allows you to terminate loops early based on conditions, giving you more control over your program's execution.
7+ registered 
