How Can I "Unset" a String Variable in Atari BASIC

[pixelmischief]

I can't figure out how to tell BASIC to "forget" a string variable.  Once I do, "DIM A$(10)", that seems to be permanent.  A$ is tattooed until a cold boot.  What can I do here?

 

[pixelmischief]

Nevermind.  A next RUN clears all of the string variables set at the READY prompt.

Edited May 17, 2020 by pixelmischief

[Rybags]

CLR will work but you lose all your other variables as well so limited usefullness.

 

Also you only have the 128 variable names, and even if you stop using one it'll still be taking up the entry in the name table.  Though I can't say I've ever run out.

But it can be freed up by LISTing then ENTERing your program back from a storage device.

 

Generally if you have some work where you want a big string e.g. for supporting data setup or something you could do it early on then issue a CLR.

[pixelmischief]

Thanks, my man!

[Graham Dearsley]

You may also want to set the length that BASIC has stored for a string back to zero, at some point, without CLRing the string and you can do that with A$="". The LEN function will then report the length as zero

[Kyle22]

CLR.

 

[JamesD]

IDK about Atari BASIC, but on Microsoft BASIC, you could reserve a specified amount of memory, and you could use PEEK and POKE to access data in that memory.
This was used on the TRS-80 for a dungeon crawler so it could go between the town (tavern?), and exploration modules... Temple of Apshai maybe?
 

Edited June 10, 2020 by JamesD

[+David_P]

There are techniques to reserve memory (sometimes you need page aligned space) as well as using strings.  The ADR command gives the address of the string, which permits manipulation of data within the string via PEEK and POKE, as well.