Unit unit1; interfaceuses windows, messages, sysutils, variants, classes, graphics, controls, forms, dialogs, stdctrls; Type tform1 = Class (tform) button1: tbutton; button2: tbutton; button3: tbutton; button4: tbutton; button5: tbutton; Procedure button1click (Sender: tobject); Procedure upload (Sender: tobject); Procedure button3click (Sender: tobject ); procedure button4click (Sender: tobject); Procedure button5click (Sender: tobject); end; var form1: tform1; implementation {$ R *. DFM} {pair of characters} procedure tform1.button1click (Sender: tobject); var C: Char; begin C: = 'a'; C: = char (charlower (pchar (c); showmessage (c); {A} end; {pair of character constants} procedure tform1.button2click (Sender: tobject); var C: Char; begin C: = char (charlower (pchar ('A'); showmessage (c); {A} end; {pair of character arrays} procedure tform1.button3click (Sender: tobject ); vaR arr: array [0 .. 2 + 1] of char; begin arr: = 'abc'; charlower (ARR); showmessage (ARR); {ABC} end; {pair of strings} procedure tform1.button4click (Sender: tobject); var STR: string; begin STR: = 'abc'; charlower (@ STR [1]); showmessage (STR); {ABC} end; {sysutils of Delphi. lowercase} procedure tform1.button5click (Sender: tobject); var STR: string; begin STR: = 'abc'; STR: = lowercase (STR); showmessage (STR ); {ABC} end; end.