PHP regex unexpected match

Question

i have a regex in my php code that should match every number and all "operators" +-*/^r() my regex looks like this

/(?:(\d+(?:\.\d+)|(\+)|(-)|(\*)|(\/)|(\^)|(r)|(\()|(\))))/

and when tested with the string preg_match_all($expression,"2+2",$results) it gives me back

Array
(
    [0] => Array
        (
            [0] => '+'
        )

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

    [2] => Array
        (
            [0] => '+'
        )

    [3] => Array
        (
           [0] => ''
        )

    [4] => Array
        (
            [0] => ''
    )

    [5] => Array
        (
            [0] => ''
        )

    [6] => Array
        (
            [0] => ''
        )

    [7] => Array
        (
            [0] => ''
        )

    [8] => Array
        (    
            [0] => ''
        )

    [9] => Array
        (
            [0] => ''
        )

)

When (if it works right) i should be getting this

Array
(
    [0] => Array
        (
            [0] => '2'
            [1] => '+'
            [2] => '2'
        )

    [1] => Array
        (
            [0] => '2'
            [1] => ''
            [2] => '2'
        )

    [2] => Array
        (
            [0] => ''
            [1] => '+'
            [2] = > ''
        )

    [3] => Array
        (
           [0] => ''
           [1] => ''
           [2] => ''
        )

    [4] => Array
        (
           [0] => ''
           [1] => ''
           [2] => ''
        )
    ...

)

Note, it returns similar behaviour for all of the operators, it seems to ignore the numbers entirely

Note, I DO need separate capture groups so i have different match indexes for each result

Answer 1

you can simply do this:

$pattern = '~\d+(?:\.\d+)?|[-+*/^r()]~';