Knowledge Check: Module 18 - Function Return Values

What is the main purpose of the return statement in a Python function?

To print output directly to the console. To send a value back from the function to where it was called. To stop the entire script's execution immediately. To define a new variable within the function.

Consider this function:
def add_numbers(x, y):
result = x + y
return result

How would you store the value returned by calling add_numbers(5, 3) into a variable named total?

print(add_numbers(5, 3)) result = add_numbers(5, 3) total = add_numbers(5, 3) add_numbers(5, 3) -> total

What happens if a function doesn't have an explicit return statement?

It causes a syntax error. It implicitly returns the value 0. It implicitly returns the special value None. It returns the last calculated value in the function.

What will be printed by the following code?
def greet(name):
message = "Hello, " + name
# No return statement here

result = greet("Alice")
print(result)

Hello, Alice None An empty string "" It will cause an error.

Can a function return multiple values in Python? If so, how are they typically returned?

No, a function can only return a single value. Yes, by using multiple return statements. Yes, often as a tuple (or list/dictionary). Yes, by separating them with commas without a return keyword.

What does the return statement do to the execution flow of a function?

It pauses the function, allowing it to be resumed later. It immediately stops the execution of the function and goes back to the calling code. It restarts the function from the beginning. It continues execution until the end of the function block, then returns.

Consider the function:
def check_number(num):
    if num > 10:
        return "Large"
    elif num > 5:
        return "Medium"
    else:
        return "Small"

What is the value of check_number(7)?

"Large" "Medium" "Small" None

Why is it generally better to use return to get a result from a function rather than printing it inside the function?

Printing is slower than returning. Printing can cause errors if the console is not available. Returning makes the function more reusable, as the calling code can decide what to do with the result (store, print, use in calculations). Returning uses less memory than printing.

What value is returned by return without any expression after it (i.e., just return)?

0 True None It causes a SyntaxError.

If you have result = calculate_area(10, 5), what does this imply about the calculate_area function?

It must print the calculated area. It must have exactly two parameters named length and width. It must use a return statement to send back the calculated area. It must not take any arguments.

Module 18: Function Return Values

Knowledge Check

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