Data commit

Task/Call-an-object-method/Delphi/call-an-object-method.delphi

@@ -0,0 +1,60 @@
+{Simple stack interface}
+
+type TSimpleStack = class(TObject)
+ private
+  FStack: array of integer;
+ protected
+ public
+  procedure Push(I: integer);
+  function Pop(var I: integer): boolean;
+  constructor Create;
+ end;
+
+
+{ TSimpleStack implementation }
+
+constructor TSimpleStack.Create;
+{Initialize stack by setting size to zero}
+begin
+SetLength(FStack,0);
+end;
+
+function TSimpleStack.Pop(var I: integer): boolean;
+{Pop top item off stack into "I" returns False if stack empty}
+begin
+Result:=Length(FStack)>=1;
+if Result then
+	begin
+	{Get item from top of stack}
+	I:=FStack[High(FStack)];
+	{Delete the top item}
+	SetLength(FStack,Length(FStack)-1);
+	end;
+end;
+
+procedure TSimpleStack.Push(I: integer);
+{Push item on stack by adding to end of array}
+begin
+{Increase stack size by one}
+SetLength(FStack,Length(FStack)+1);
+{Insert item}
+FStack[High(FStack)]:=I;
+end;
+
+
+procedure ShowStaticMethodCall(Memo: TMemo);
+var Stack: TSimpleStack;	{Declare stack object}
+var I: integer;
+begin
+{Instanciate stack object}
+Stack:=TSimpleStack.Create;
+{Push items on stack by calling static method "Push"}
+for I:=1 to 10 do Stack.Push(I);
+{Call static method "Pop" to retrieve and display stack items}
+while Stack.Pop(I) do
+	begin
+	Memo.Lines.Add(IntToStr(I));
+	end;
+{release stack memory and delete object}
+Stack.Free;
+end;