DeferredReturn

Misconception:

A return statement in a function does not return immediately, but it waits until the function finishes executing.

A return statement in the middle of a function doesn't return immediately

A return statement immediately returns from the function

A return statement returns immediately, for example:

def tick(value: int):
    if value <= 0:
        return

    value -= 1

    if value == 0:
        ring_bell()

In the above code, if value <= 0, then the return statement executes and returns from the function immediately, i.e., lines after the return statement will not be executed.

Note for advanced students: The only situation where return does not return immediately is if the return statement is located inside a try block with a corresponding finally block. In that case, the finally block will execute before returning.

This misconception can provide a good opportunity to discuss statement sequences as a key aspect of imperative programming.

The misconception can also be an opportunity to point out the fact that return statements located inside a try block with a corresponding finally block indeed do not return immediately. However, a full-fledged discussion of the details of exception handling may be too advanced at the time students hold this misconception.

Python

plr3.8

7.6 The return statement

Return Control Flow Function Call

method involving return statement

Java

DeferredReturn