break
is used to end a loop prematurely while return
is the keyword used to pass back a return value to the caller of the function. If it is used without an argument it simply ends the function and returns to where the code was executing previously.
There are situations where they can serve the same purpose but here are two examples to give you an idea of what they are used for
Using break
Iterating over a list of values and breaking when we’ve seen the number 3
.
def loop3():
for a in range(0,10):
print a
if a == 3:
# We found a three, let's stop looping
break
print "Found 3!"
loop3()
will produce the following output
0
1
2
3
Found 3!
Using return
Here is an example of how return
is used to return a value after the function has computed a value based on the incoming parameters:
def sum(a, b):
return a+b
s = sum(2, 3)
print s
Output:
5
Comparing the two
Now, in the first example, if there was nothing happening after the loop, we could just as well have used return
and “jumped out” of the function immediately. Compare the output with the first example when we use return
instead of break
:
def loop3():
for a in range(0, 6):
print a
if a == 3:
# We found a three, let's end the function and "go back"
return
print "Found 3!"
loop3()
Output
0
1
2
3