Pointer in Basic

[Kernelpanic]

Has anyone ever dealt with pointers in Basic?

Actually there are no pointers in Basic like in C, but maybe they can be imitated. I've tried this now with VarPtr, Peek and Poke, and I didn't find any error in my exercise to achieve this. I don't see any at the moment either. Access to the memory address is basically like in C, and I can also change the content.

Pointers are a powerful, but also dangerous, tool in C! One could definitely good use them in Basic too. I think so.

I would be grateful to anyone who is interested and takes a look at the program if they could point out whether and if so, where I made a mistake in my thinking.

The explanations/comments are of course in German, so I can understand what's going on. 

Code: (Select All)

'Zeigerbeispiel in Basic - 16. Juli 2023
'Mit VarPtr und Peek und Poke ist es moeglich Zeiger in
'Basic nachzuahmen.

$Console:Only
Option _Explicit

Dim As Long zahl1, zahl2, wert, wert2
Dim As Long speicherAdresse, speicherAdresse2

Locate 2, 3
Input "Zahl 1: ", zahl1

Locate 3, 3
Input "Zahl 2: ", zahl2

Locate 5, 3
Print Using "Zeige Zahl 1: ### -- Zahl 2: ### "; zahl1, zahl2

'Adresse der Zahl im Speicher ermitteln
speicherAdresse = VarPtr(zahl1)

'Speicheradresse anzeigen
Locate 6, 3
Print "Speicheradress Zahl 1: ", speicherAdresse

'wert wird der Inhalt der Speicheradresse zugewiesen
wert = Peek(speicherAdresse)

Locate 8, 3
Print "Inhalt der Speicheradresse: ", wert

'wert erhoehen
wert = wert * 2

'Neuen Wert in die Speicheradresse einfuegen
Poke (speicherAdresse), wert

'Neuen Inhalt anzeigen
Locate 9, 3
Print "Neuer Inhalt in der Speicheradresse (Inhalt * 2): ", wert

'Speicheradresse der 2ten Variablen ermitteln
speicherAdresse2 = VarPtr(zahl2)
wert2 = Peek(speicherAdresse2)

'Inhalt der Speicheradresse
Locate 11, 3
Print "Inhalt der 2ten Speicheradresse: ", wert2

Locate 12, 3
Print "Jetzt auf die Adresse von Zahl 2 zugreifen, um den Inhalt zu aendern."

'Der 2ten Variablen den Wert von wert2 von der
'ersten Speicheradresse zuweisen
Locate 14, 3
wert2 = Peek(speicherAdresse)
Print "2te Variable hat jetzt den selben Wert wie Zahl 1: ", wert2

End