PHP: get array with preg_* functions

Question

I want to parser and get a two-dimensional matrix using regular expresions of PHP. But I really don't know to parser and get a array(unidimensional). For example, I have this string:

    $str = {a}&{b}&{c}&{d&};

and I want to convert to array like this:

    array( 'a', 'b', 'c', 'd&' )

The pattern should be this:

    $pattern = '#(({[^}]+})(?:&(?1))*#';

The pattern matches correctly but I can't get all elements with $matches parameter:

    preg_match_all( $pattern, $str, $matches );
    print_r( $matches );

Output:

    Array
    (
        [0] => Array
            (
                [0] => {a}&{b}&{c}&{d&}
            )

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

    )

I try to solve this problem involving the recursive pattern with parentheses.

    $pattern = '#(({[^}]+})(?:&((?1)))*#';

Output:

    Array
    (
        [0] => Array
            (
                [0] => {a}&{b}&{c}&{d&}
            )

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

        [2] => Array
            (
                [0] => d&
            )

    )

Only is gotten the last element of array. The option flags PREG_PATTERN_ORDER or con PREG_SET_ORDER haven't solved my problem.

Is there any way to get the array of elements?

Greetings and thanks!

Just use the pattern that's been used [here](http://stackoverflow.com/a/14952740/) like this [`\{((?:[^{}]|(?R))*)\}`](http://regex101.com/r/eN8gV4), it will even match nested `{}` :D — HamZa, Nov 07 '13 at 23:33

score 2 · Answer 1 · answered Nov 07 '13 at 23:38

2

Uh, your regex is way overcomplicated.

$pattern = "#{([^}]+)}#";
$data = "{a}&{b}&{c}&{d&}";
preg_match_all($pattern, $data, $matches);
print_r($matches);

Output:

Array
(
    [0] => Array
        (
            [0] => {a}
            [1] => {b}
            [2] => {c}
            [3] => {d&}
        )

    [1] => Array
        (
            [0] => a
            [1] => b
            [2] => c
            [3] => d&
        )

)

So your desired output is just $matches[1].

answered Nov 07 '13 at 23:38

Sammitch

30,782
7
50
77

Thanks. Then, should I do two passes to parse $data? Because $data = "{a}|{b}&{c}|{d&}"; is a string succesful. After, I should check '&' characters. – xgbuils Nov 07 '13 at 23:50

Casimir et Hippolyte · Accepted Answer · 2013-11-08T00:20:05.970

1

You can use this pattern which captures the content inside curly brackets and checks the syntax (i.e. {..}&{..}&{..}&{..}) :

preg_match_all('~\G{([^}]+)}(?:&|$)~', '{a}&{b}&{c}&{d&}', $result);

\G means "contiguous to a precedent match or at the start of the string". Thus, gaps are not allowed and the syntax is checked by the pattern.

The array you are looking for is $result[1]

edited Nov 08 '13 at 00:20

answered Nov 08 '13 at 00:12

Casimir et Hippolyte

88,009
5
94
125

Oh, thanks! this works. I should review the issue escape sequences. – xgbuils Nov 08 '13 at 00:29

score 0 · Answer 3 · answered Nov 07 '13 at 23:39

for your former question, try:

$str = "a&b&c&d&word";
$pattern = '/[^&]+/';
preg_match_all( $pattern, $str, $matches );
print_r( $matches );

get:

Array
(
    [0] => Array
        (
            [0] => a
            [1] => b
            [2] => c
            [3] => d
            [4] => word
        )
)

PHP: get array with preg_* functions

3 Answers3