php - 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!

Answer 1

呃，你的正则表达式太复杂了。

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

输出：

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

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

)

所以你想要的输出只是$matches[1].

Answer 2

您可以使用此模式捕获大括号内的内容并检查语法（即{..}&{..}&{..}&{..}）  ：

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

\G表示“与先前匹配或在字符串的开头连续”。因此，不允许有间隙，语法由模式检查。

您正在寻找的数组是$result[1]

Answer 3

对于您以前的问题，请尝试：

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

得到：

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