Regex for capturing specific values in PHP

Question

I trying to get the values from a string by a regular expression pattern, it works, but it will return all matched strings (I mean the string with {} too)

this is the string:

dashboard/admin/{content}/category/{category}/posts

Regex pattern:

/{(.*?)}/

and the PHP code is :

    preg_match_all('/{(.*?)}/', $url, $matches, PREG_SET_ORDER, 0);

and the content of $matches is:

array:2 [
  0 => array:2 [
    0 => "{content}"
    1 => "content"
  ]
  1 => array:2 [
    0 => "{category}"
    1 => "category"
  ]
]

but I want to have an array like this:

array:2 [
  0 => "content",
  1 => "category"
]

So what have you tried? Just iterate over the matches and select `$match[1]` will do the trick to transform your actual result to the desired one. — Kryptur, May 20 '19 at 11:22

score 1 · Answer 1 · answered May 20 '19 at 11:22

1

Remove the PREG_SET_ORDER so that the index's are by capture group.

preg_match_all('/{(.*?)}/', 'dashboard/admin/{content}/category/{category}/posts', $matches);

with this use $matches[1], because 1 will be the first capture group. The 0 index will be all full matches.

answered May 20 '19 at 11:22

user3783243

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it shows me exactly that result :( – MajAfy May 20 '19 at 11:28
`print_r($matches[1])` => `Array ( [0] => content [1] => category )` it shows to me @MajAfy. – bobble bubble May 20 '19 at 11:34
@MajAfy Not sure what you mean. This is exactly what you asked for. All matches under 1 index. https://3v4l.org/kdBQH, or the `I want to have an array like this` is incorrect. – user3783243 May 20 '19 at 11:58

score 1 · Accepted Answer · answered May 20 '19 at 11:23

Use lookaround:

$url = 'dashboard/admin/{content}/category/{category}/posts';
preg_match_all('/(?<={).*?(?=})/', $url, $matches, PREG_SET_ORDER, 0);
print_r($matches);

Output:

Array
(
    [0] => Array
        (
            [0] => content
        )

    [1] => Array
        (
            [0] => category
        )

)

score 0 · Answer 3 · answered May 20 '19 at 12:56

You could make use of \K and a single positive lookahead to assert what is on the right is a }:

{\K[^}]+(?=})

Regex demo

$url = 'dashboard/admin/{content}/category/{category}/posts';
preg_match_all('/{\K[^}]+(?=})/', $url, $matches);
print_r($matches[0]);

Result:

Array
(
    [0] => content
    [1] => category
)

Php demo

Regex for capturing specific values in PHP

3 Answers3