RE: [PHP4BETA] is string numeric

Harold writes: > > someone emailed me a solution with what i was looking for.. > > $a="12345"; > if (eregi ("\D", $a)): > // not only numbers in string > else: > // only numbers in string > endif; This won't work. \D is perl regexp syntax, not POSIX, so you'd need to use [[:digit:]] or [0-9] instead of \D. Also, this just checks for the existence of a digit in the string; it doesn't say anything about all the elements being digits. You could reverse the logic with the ^ operator to make it look for any non-numeric data ([0-9] means "match any digit", and [^0-9] means "match any non-digit"). <?php $string = '123435'; if ( !ereg( '[^0-9]', $string ) ) { echo "String is pure numeric.\n"; } else { echo "String contains non-numeric data.\n"; } ?> Alternatively, you could skip the regexp (which is moderately expensive) altogether by simply casting the string to int, then casting back to string. If it's still the same, then it's all numeric since any non-numeric elements would be lost in the cast: <?php function is_numeric( $str ) { return ( (string) (int) $str == $str ); } echo is_numeric( $string ) ? "Yes" : "No" ; ?> -- +----------------------------------------------------------------+ |Torben Wilson <torben@php.net> Netmill iTech| |http://www.coastnet.com/~torben http://www.netmill.fi| |Ph: 1 250 383-9735 torben@netmill.fi| +----------------------------------------------------------------+