how to check if a string of a number has 10 characters in php

Question

I am struggeling at implementing a check on a textbox.

I want to check if the phone number has a length of 10 characters, contains my country base number and if it is actually a numerical value.

i only know how to check if it is a number.

                    if(ctype_digit($telefon) && ctype_digit($telefon)=="10"){
                          ...
                        
                    } else {
                        echo "Invalid phone number";
                    }
            

Answer 1

Using PHP's 'strlen($string)' function would count every character including any format notations

https://www.w3schools.com/PHP/func_string_strlen.asp