RETURN: Your Subroutine's Homecoming Ticket
Taken a detour with GOSUB? Had a fun time in your subroutine? Don't forget your return ticket home—the RETURN command! This essential tool is the counterpart to GOSUB, marking the end of your subroutine and whisking your program execution right back to the line after the original GOSUB call. Think of it as the express train back to your main program!
Syntax
RETURN
(That's it! No parameters needed.)
Applications
The RETURN command is crucial for:
- Exiting subroutines: Without
RETURN, your program would be stuck in the subroutine forever! - Modular code: Breaking your program into reusable subroutines makes it more organized and easier to understand.
RETURNis essential for this modularity. - Creating functions: While Commodore 64 BASIC doesn't have formal functions, you can simulate them using
GOSUBandRETURN, returning a calculated value in a variable.
Code Examples
1. Basic Subroutine Return:
10 PRINT "Start"
20 GOSUB 50 :rem Jump to the subroutine at line 50
30 PRINT "End"
40 END
50 PRINT "This is a subroutine"
60 RETURN :rem Return to line 30
This simple example demonstrates the basic flow of GOSUB and RETURN.
2. Returning a Calculated Value:
10 INPUT "Enter a number: "; N
20 GOSUB 100 :rem Calculate the square of N
30 PRINT "The square is "; S
40 END
100 S = N * N :rem Calculate square
110 RETURN :rem Return with the value in S
Here, the subroutine acts like a function, calculating the square and returning the result in S.
RETURN in the Wild: The Game Level Architect
Imagine you're designing a multi-level game for the Commodore 64. You could use GOSUB/RETURN pairs to manage each level as a separate subroutine. When the player completes a level, the RETURN statement would bring them back to the main game loop to progress to the next level.
Don't leave your subroutines stranded! With RETURN, you can ensure a safe and smooth return to the main program, allowing you to build modular, organized, and reusable code. It's like a compass for your program's execution, guiding it back to the right path. So embrace the power of RETURN and create well-structured Commodore 64 masterpieces!
