SRL Archive - News and General

Is there a way to change a variable that is named with a string?

Ex.

program new;
var
  s : string;

procedure ChangeVar(var varname : variant; changeto : variant);
begin
  varname := changeto;
end;

begin
  ChangeVar('s', 'likethis..but it dosent work.');
end.

program New;

procedure ChangeString(var toReplace: string);
begin
  toReplace := 'changed';
end;

var
  str: string;

begin
  str := 'lalalala';
  WriteLn(str);
  ChangeString(str);
  WriteLn(str);
end.

The same works for any other variable type (you had the idea right anyways).

No I know how to do that already.

I mean change the variable via string…

program New;

var
  str : string;

procedure ChangeVar(var varname : string; changeto : string);
begin
  varname := changeto;
end;

begin
  str := 'hey'
  writeln(str);
  changevar('str', 'hey1';
  writeln(str);
end.

That, in theory, would change varname to changeto.
But technically, it dosen't.

That's because you're not feeding in the str variable, you're giving it the string 'str' instead. Remove the quotes and it'll work fine.

I understand that. I want it to be able to dynamically change them for my DaInclude SetVar and GetVar rc commands. I think I almost found the solution but most likely, it won't work.

You can change variables through procedures like that just how I had it. You just have to make sure you're feeding a variable for the parameter that takes a var name: type instead of just a piece of data like 'str'.

I don't think you understand what I am saying…

Yes that woulds woohoo but I knew how to do that already.

Let's take your procedure.

ToReplace has to be static. You cant set it by string. That's what I want.
So that you can set a variable via string like

procedure setvar(varname : string);
begin
s := 'hey';
end;

then this would be in main loop

setvar(s);

The code you just pasted works fine. I don't know what you're trying to do if it's not that.

program New;

var
  str: string;
  
procedure setVar(var s: string);
begin
  s := 'hey';
end;

begin
  setVar(str);
  WriteLn(str);
end.

Successfully compiled (31 ms)
hey
Successfully executed

Alright, go on msn Method.
And add me [email]kylewollaston@hotmail.com[/email]
It takes to long to talk on this.

what he means is.

var
tobechanged:string;

setvar(currentvar,newvartype):variant

tobechanged= string
he wants to change tobechanged from a string to a new var like an integer.

so he wants to

 setvar(tobechanged,integer) 

Am i right da owner?

Heh, nope. It's kinda hard to explain..

I actually want it to set any var that is specified in the parameters of a function with a string.

Why would you want to change the var's name in the first place?

I don't want to change the variables name. I want to change it's contents.

Like wtf, this is how you change a var (this is a string example)

s := 'hi';

procedure change(var s: String; toWhat: String);

Begin
  s := toWhat;
End;

i figured out what he wants.

var 
zasz:string; // this = what to input in VARTOEDIT part.

procedure edit(vartoedit,text:string);
begin  
  vartoedit := text; // zasz = me!
end;

begin
  edit(zasz,'me!');
end.

I know this is what he means now.

You can use variants… You can't represent an identifier with a string, e.g "turn the string into the var"…

S: String;
VarToChange: TVariant;

Procedure change(Var Change: TVariant; To: String);

Begin
  Change := To;
End;

Begin
  S := '2';
  VarToChange := S;
  Change(VarToChange, '3');
End.

You get what he means now n3ss3s???

Nvm guys, you just don't get it.

n3ss3s and zasz, you guys are wrong..

zasz has got the point of what i want though.

Something like this will work fine..

var
  s: string;

procedure edit(var variable: string; text: string);
begin
  variable := text;
end;

begin
  edit(s, '1');
  writeln(s);
  edit(s,'2');
  writeln(s);
end.

Or did I not understand you correctly?

Nope it dosen't work the way I want.
This does though.
Just requires a little extra work and takes longer tho :/.

Program New;

type
  variable = record
    name : string;
    contents : variant;
  end;

var
  variables : array [0..1] of variable;

procedure SetVars;
begin
  variables[0].name := 'var1';
  variables[0].contents := 'var1contentsbefore';
  variables[1].name := 'var2';
  variables[1].contents := 'var2contentsbefore';
end;

procedure SetVar(name : string; towhat : variant);
var
  i : integer;
begin
  for i := 0 to high(variables) do
  begin
    if variables[i].name = name then
    begin
      writeln('Before: ' + variables[i].contents);
      variables[i].contents := towhat;
      writeln('After: ' + variables[i].contents);
      exit;
    end;
  end;
end;

begin
  setvars;
  setvar('var2', 'var2contentsafter');
  writeln('');
  setvar('var1', 'var1contentsafter');
end.

Now he pmed me I know what he means :p


He wants to represent an identifier with a string. Identifiers are just 'addresses' for the values in RAM, representing an identifier with something else means representation of presentation…

Tell me what use do you have for it and maybe we can try to think of an efficient solution…

Read my post before yours.

Program New;


var
  variables : array[0..1] of string;

procedure SetVars;
begin
  variables[0]:=  'var1contentsbefore';
  variables[1] := 'var2contentsbefore';
end;

procedure WritelnVars;
begin;
  Writeln(Variables[0]);
  Writeln(Variables[1]);
end;

procedure SetVar(name : string; towhat : variant);
var
  i : integer;
begin
  case name of
    'var1' : Variables[0] := ToWhat;
    'var2' : Variables[1] := ToWhat;
  end;
end;

begin
  setvars;
  writeln('Before : ');
  WritelnVars;
  setvar('var1', 'var1contentsafter');
  setvar('var2', 'var2contentsafter');
  Writeln('After: ');
  WritelnVars;
end.

Yeah, that's basically what I had without the record and neater :p.