RegExr with minimum 2 letter and optional letters, but no other letters?

Question

I want a regex for an text, that allow it, if atleast 1 word with 2 letters are inside, and minimum 25 letters or digits and also allow (0-9äöü,.' -), if other letters or digits there, it should be give an error.

---

Example:

correct:

• John Doe
• Max Müstermann
• John-Frank' Doe.

false:

• John/Doe

Regex:

• Wordregex: ([a-z]{2})\w+
• allowed Items: [äöü0-9,.' -]
• max length: {25,999}

if(preg_match("/([A-Za-z]{2})\w+/",$text)){
    if(!preg_match("/[a-zäöüA-ZÄÖÜ,.' -]/g",$text)){echo 'error';}
else{echo'error';}

I'm not sure how to get the solution in code.

Answer 1

What you might do is use a positive lookahead to assert the length of 25 - 999 and also assert that there are 2 consecutive [a-z]

Then match your character class [a-zA-Z0-9äöü,.' -]+ with the allowed items adding a-z and A-Z to it.

^(?=.{25,999})(?=.*[a-z]{2})[a-zA-Z0-9äöü,.' -]+$

• ^ Start of string
• (?=.{25,999}) Positive lookahead, assert 25 - 99 characters
• (?=.*[a-z]{2}) Positive lookahead, assert 2 times [a-z]
• [a-zA-Z0-9äöü,.' -]+ Match any of the listed 1+ times
• $ End of string

Regex demo | Php demo

For example (I have made the strings longer to account for the minimum length of 25)

$strings = [
    "This is a text with John Doe",
    "This is a text with Max Müstermann ",
    "This is a text withJohn-Frank' Doe.",
    "This is a text with John/Doejlkjkjlk",
];
$pattern = "/^(?=.{25,999})(?=.*[a-z]{2})[a-zA-Z0-9äöü,.' -]+$/";
foreach ($strings as $string) {
    if (preg_match($pattern, $string)) {
        echo "Ok ==> $string" . PHP_EOL;
    } else {
        echo "error" . PHP_EOL;
    }
}

Result

Ok ==> This is a text with John Doe
Ok ==> This is a text with Max Müstermann 
Ok ==> This is a text withJohn-Frank' Doe.
error