- var_dump: documentation ( source)
- filter_var: documentation ( source)
<?php
var_dump(filter_var('123.5645454', FILTER_VALIDATE_REGEXP,array("options"=>array("regexp"=>"/^([1-9][0-9]*|0)(\.[0-9]{10})?$/"))));
var_dump(filter_var('abc34', FILTER_VALIDATE_REGEXP,array("options"=>array("regexp"=>"/\d+(?:\.\d{1,2})?/"))));
var_dump(filter_var('123.100', FILTER_VALIDATE_REGEXP,array("options"=>array("regexp"=>"~^\\d+(?:\\.\\d{1,10})?$~"))));