Return number with Regular Expression

Question

I have a list of articles from Art. 1 to Art. 2.040., but in each article there are other numbers.

I would like to make an expression that: 1 - Capture the numbers always after the string "Art. " until the space after the number; 2 - Exclude the points and the numeral symbol "º";

I would like to make a regular expression that returns only the article numbers.

This is the code I used, but in some articles it generates a strange number

$str = preg_replace('/[^0-9]/', '', $novalinhas);
$artigo = $str;

But like this, it takes all the numbers from the string

---

I solved the question like this:

              preg_match('/[0-9]+/', $novalinhas, $matches);
              $artigo = implode(' ',$matches);
              echo $artigo;

But I don’t know if it’s the best way.

Answer 1

I haven’t done PHP in a while, here goes:

$artigos = [
    "Art. 1 lala 23",
    "Art. 2 lala 23",
    "Art. 3 lala 23",
    "Art. 4345 lala 23",
    ];
$artigos_len = count($artigos) -1;

for ($i=0; $i <= $artigos_len; $i++) {
    preg_match("/Art\. (\d+)/i",$artigos[$i],$match);
    echo "<ul class='artigo {$match[1]}'></ul>\n\r"

}

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the important part here is preg_match("/Art\. (\d+)/i",$artigos[$i],$match); this line takes, from each item in the article list, a regular expression that has that have "Art. NUMERO" but do not care what goes beyond that.

(\d+) refers to a group of numbers that may have one or more digits, serving for us later to use the $match[1] where 1 is the number of this same group.