Mega Code Archive
What Swapping two variables without pointers or a third one
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Title: What??? Swapping two variables without pointers or a third one?
Question: How to swap two integers without a temporary variable or pointers?
Answer:
Yes, its possible to swap the values of two variables without using a third one or swapping pointers.
How??? The answer is: using xor!!!
Place a label and a button on a form, and put this on Buttons click event.
//------------------------------
procedure TForm1.Button1Click(Sender: TObject);
var
var1 : integer;
var2 : integer;
begin
var1 := 19;
var2 := 564;
var1 := var1 xor var2;
var2 := var1 xor var2;
var1 := var1 xor var2;
// Theyre swapped!!!
Label1.Caption := 'Var1 = ' + IntToStr(var1) + '; Var2 = ' + IntToStr(var2);
end;
//------------------------------
Try this!
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