s := '123'; s := s + '0' + s; s := s + s; writeln ( s );
s := '123'; s := s + s[2] + s + s[3]; writeln ( s );
s := '12345'; n := Length(s) + Length('456'); writeln ( n );
s := '123456789'; s1 := 'abcdef'; s := Copy(s,5,2) + '0' + Copy(s1,3,3); writeln ( s );
s := '123456'; q := 'abc'; Delete ( s, 2, 3 ); Insert ( s, q, 2 ); writeln ( q );
s := '123456789'; Delete ( s, 1, 2 ); n := Pos ( '6', s ); writeln ( n );
s := '123456789'; n := Pos ( '456', s); Delete ( s, n+2, 3 ); writeln ( s );
s := '123456'; while Length(s) > 0 do begin Delete ( s, 1, 2 ); writeln ( '1' ) end;
c := 0; repeat ... if p <> 0 then begin c := c + 1; Delete ( S, 1, p+1) end; until p = 0;
c := 0; for k:=1 to Length(S) do begin if S[k] = '0' then ... end;
Q := '123456789'; S := '1'; for k:=2 to 9 do begin ... end;