Sha256: 6e8d2daaa2af4307fd56e83d878e0c49e6b5e4b9a61479a8a94b4fe1625dc616
Contents?: true
Size: 761 Bytes
Versions: 104
Compression:
Stored size: 761 Bytes
Contents
unit uISBNVerifier;
interface
type
TIsbn = class
public
class function isValid(aInput: string): Boolean;
end;
implementation
uses sysutils, RegularExpressions;
{ TIsbn }
class function TIsbn.isValid(aInput: string): Boolean;
var
wrkStr: string;
sum,
weight,
digit,
i: integer;
begin
result := false;
wrkStr := aInput.replace('-','');
if TRegex.IsMatch(wrkStr, '^(\d{9}[\dX])$') then
begin
sum := 0;
weight := 10;
digit := 0;
for i := low(wrkStr) to high(wrkStr) do
begin
if (wrkStr[i] = 'X') and (i = 10) then
digit := 10
else
digit := string.ToInteger(wrkStr[i]);
sum := sum + (digit * weight);
dec(weight);
end;
result := sum mod 11 = 0;
end;
end;
end.
Version data entries
104 entries across 104 versions & 1 rubygems