Get numbers that immediately follow @ symbol in string

Question

Imagine I have a textarea with the following value.

@3115
Hello this is a test post.

@115
Test quote

I'm trying to find a way in PHP using regex that will get the numeric value that comes after the '@' symbol even if there's multiple symbols.

I imagine storing the values that are returned from the regex into an array is what I'm looking for.

Actually can you clarify if you want *all* the values or just the first? I assumed you wanted all of them, but rereading your post it's ambiguous? — Martin, May 23 '17 at 16:25

Ethan · Answer 1 · 2017-05-23T16:29:13.260

Try this:

$str = <<<EOF
@3115
Hello this is a test post.

@115
Test quote
EOF;

preg_match_all('/@(\d+)/', $str, $matches);
var_dump($matches[1]); // Returns an array like ['3115', '115']

The preg_match_all function gets all the occurrences of the regex in the input string and returns the capture group.

Regex breakdown

/@(\d+)/

@ matches the character literally.
( starts a capture group.
\d matches a digit (equal to [0-9]).
+ means the digit can be repeated one or more times.
) ends the capture group.

Martin · Accepted Answer · 2022-08-01T08:39:12.737

2

(Using a preg_match_all function as an example, but the function doesn't matter, the Regex within does:)

  $inputString = "@3115
        Hello this is a test post.
        @115
       Test quote";
  preg_match_all("/@(\d+)/",$inputString,$output);
  //$output[1] = "3115";      
  //$output[2] = "115";

This will find a @ character, and then find \d which is any numerical value, and then + means to catch [the numerical value] one or more times. the () makes this a capture group so will only return the number found and not the @ preceeding it.

edited Aug 01 '22 at 08:39

answered May 23 '17 at 16:19

Martin

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This is misleading. `preg_match()` will not make multiple matches. – mickmackusa Jul 31 '22 at 15:35

score 0 · Answer 3 · answered Jul 31 '22 at 15:40

Match the @, forget it with \K, then match one or more digits as the fullstring match.

Code: (Demo)

$str = <<<TEXT
@3115
Hello this is a test post.

@115
Test quote
TEXT;

preg_match_all('/@\K\d+/', $str, $matches);
var_export($matches[0]);

Output:

array (
  0 => '3115',
  1 => '115',
)

Get numbers that immediately follow @ symbol in string

3 Answers3

Regex breakdown