Simple year format validation using PHP -

i validate if given year input in specific format or not. format of year should yyyyad or yyyybc (eg: 2013ad) - 4 numbers , ad/bc without space in between. should return true if input in correct format, else false should returned. (some expected incorrect formats are; 123ad, xyzad, ad2013, ad, 2013, @123ad, 2013ad). how can achieve this?

thanks in advance...:)

use regex expression such as/^\d{4}(ad|bc)$/.

explanation of regex:

• ^ - start of string
• \d{4} - digit 0 9 repeated 4 times
• (ad|bc) - group of either string "ad" or string "bc"
• $ - end of string

code:

$input = "2013bc"; if (preg_match("/^(\d{4})(ad|bc)$/", $input, $matches)) {     echo "ok.\n";     echo "year: " . $matches[1] . "\n";     echo "ac/bc: " . $matches[2]; } else {     echo "not ok!"; }