Question

I have a string formed up by numbers and sometimes by letters.

Example AF-1234 or 345ww.

I have to get the numeric part and increment it by one.
how can I do that? maybe with regex?

Answer 1

You can use preg_replace_callback as:

function inc($matches) {
    return ++$matches[1];
}

$input = preg_replace_callback("|(\d+)|", "inc", $input);

Basically you match the numeric part of the string using the regex \d+ and replace it with the value returned by the callback function which returns the incremented value.

Ideone link

Alternatively this can be done using preg_replace() with the e modifier as:

 $input = preg_replace("|(\d+)|e", "$1+1", $input);

Ideone link