Code:
procedure TForm1.Button1Click(Sender: TObject);
var
In_File,Out_File:TextFile;
Con:string;
begin
AssignFile(In_File,'input.txt');Reset(In_File);
AssignFile(Out_File,'output.txt');Rewrite(Out_File);
while not eof(In_File) do
begin
Readln(In_File, Con);
ListBox1.Items.Add(Con);
if IsNumber(Con[1]) then Writeln(Out_File, Con);
end;
CloseFile(Out_File);
CloseFile(In_File);
//
end;
function TForm1.IsNumber(number:char) : boolean;
begin
result:=False;
if (number='0') or (number='1') or (number='2') or (number='3') or (number='4') or (number='5')
or (number='6') or (number='7') or (number='8') or (number='9') then result:=True;
end;
procedure TForm1.Button1Click(Sender: TObject);
var
In_File,Out_File:TextFile;
Con:string;
begin
AssignFile(In_File,'input.txt');Reset(In_File);
AssignFile(Out_File,'output.txt');Rewrite(Out_File);
while not eof(In_File) do
begin
Readln(In_File, Con);
ListBox1.Items.Add(Con);
if IsNumber(Con[1]) then Writeln(Out_File, Con);
end;
CloseFile(Out_File);
CloseFile(In_File);
//
end;
function TForm1.IsNumber(number:char) : boolean;
begin
result:=False;
if (number='0') or (number='1') or (number='2') or (number='3') or (number='4') or (number='5')
or (number='6') or (number='7') or (number='8') or (number='9') then result:=True;
end;