PHP regex - valid float number

Question

I want user only input 0-9 and only once \".\"

 patt = /[^0-9(.{1})]/

 1.2222 -> true
 1.2.2  -> false (only once \'.\')

help me , t

Answer 1

Why not just use is_numeric if you're not experienced with regular expressions.

As to your regex: . matches all characters, \. matches a dot. {1} is not necessary. And I have no clue what you're trying to do with [^ ... ]. Read the regular expressions tutorial if you really want to use regular expressions somewhere in your code.