Static glass Delphi

[briley]

Why isn't anything going on at the Push?

type
  TStack = record
  StackArray : array [1..5] of Integer;
  top : Integer;
end;
var MyStack : TStack;

i,a,x : Integer;

procedure Push(s : TStack;a : Integer);

begin

s.top := s.top + 1;

s.StackArray[s.top] := a;

end;

procedure Pop(s : TStack);

begin

s.top := s.top - 1;

end;
function TTop(s : TStack) : Integer;

begin

TTop := s.StackArray[s.top];

end;
begin

MyStack.top := 0;
Push(MyStack,23);

Write('TOP : ');

writeln(MyStack.top);
Readln;
end.

[derk]

Delphi record--- it's a matter, not a reference. That is, a local copy is being created within the procedure, and therefore a change in the parameter s internal procedure Push There's no impact on the state. MyStack♪

To get what you want, add. var parameter s:

procedure Push(var s : TStack;a : Integer);
begin
  s.top := s.top + 1;
  s.StackArray[s.top] := a;
end;