Regular expressions. How to find a number and add to it?

Question

Regular Expressions

Please help.
There is a line of the form It is <img src="/d/349846-2/
necessary to replace 349846, namely, add +2 to this number .
It should turn out <img src="/d/349848-2/
Thank you in advance.

Answer 1

ideone.com/DltVvA
www.php.net/preg_replace_callback

Answer 2

Something with the encoding turned out to be wrong in the question.
There is a line like <img src="/d/349822-2/
you need to replace the number 349822 and add + 2 to it, it
should work <img src="/d/349824-2/for an example. Use in php script.