Extracting an integer from a string in PHP: how to get only digits?

Hello everyone! I'm a beginner in PHP and ran into a problem. I have a string, for example: "Price: 1234 rub." or "Article #5678-90". I need to extract an integer (unsigned) from it, that is, get only the digits, discarding everything else. I tried using (int), but it only works if the string starts with a digit. If the string is "Price 100", then (int) gives 0, but I need 100. I tried using preg_match with the regex '/\d+/', but I'm not sure if that's correct, especially if there are multiple numbers in the string (for example, "Code 123, price 456"). Please advise how to reliably extract a single integer from a string? Preferably with a code example. Thanks in advance! Example strings: - "Order No. 98765" - "Amount: 1500 rubles" - "ID: 42" - "Result: 0 errors" What is the simplest and most understandable way for a beginner?