Question

I have a username textbox. It should only accept between 3 and 10 characters and it should only accept (0, 9) and (A , Z ) values or maybe (- and _),
nothing more
.

And if the user inputs a value like $%^# it should give an error
I want to do this with PHP, not Jquery. Can anyone help me with this?

I know I can use

<input name="1" type="text" value="1" maxlength="10" />

But it doesn’t give an error to the user and just filters the input value.

Thank you.

Answer 1

regular expression could work

if (preg_match("%^[A-Za-z0-9-_]{3,10}$%", $_POST["1"])) {
    // OK
} else {
    // ERROR
}