Convert string to multidimensional array to calculate date in php

Try this:

$str = 'Mon[3,9] Tue[3,9] Wed[5,9] Thu[5,11] Fri[5,11] Sat[5,11] Sun[4,10]';
// convert main string to array by explode by empty space
$arr = explode(' ', $str);

$newArr = [];

foreach ($arr as $data) {
  // to get all b/n brackets best is to use regEx
  preg_match('#\[(.*?)\]#', $data, $match);
  // for key of new array use all befor 1st bracket
  // and for content explode data b/n brackets by ','
  $newArr[strtok($data, '[')] = explode(',', $match[1]);
}

var_dump($newArr);

Result:

array(7) {  ["Mon"]=> array(2) { [0]=> string(1) "3" [1]=> string(1) "9" } 
            ["Tue"]=> array(2) { [0]=> string(1) "3" [1]=> string(1) "9" }    
            ["Wed"]=> array(2) { [0]=> string(1) "5" [1]=> string(1) "9" } 
            ["Thu"]=> array(2) { [0]=> string(1) "5" [1]=> string(2) "11" } 
            ["Fri"]=> array(2) { [0]=> string(1) "5" [1]=> string(2) "11" } 
            ["Sat"]=> array(2) { [0]=> string(1) "5" [1]=> string(2) "11" } 
            ["Sun"]=> array(2) { [0]=> string(1) "4" [1]=> string(2) "10" } 
    }

Here's a suggestion:

$days = "Mon[3,9] Tue[3,9] Wed[5,9] Thu[5,11] Fri[5,11] Sat[5,11] Sun[4,10]";
$individualDays = explode(' ', $days);
$result = [];
foreach ($individualDays as $individualDay) {
    $dates = preg_match_all('/\d+/', $individualDay, $matches);
    $result[substr($individualDay, 0, 3)] = $matches[0];
}

How it works:

• All your values are separated by a space, so we first explode by it to get an array of individual strings (Mon[3,9], Tue[3,9] and so on) we can iterate.
• The first three characters of each of those strings are the day designation and we use that as the key for our new resulting array (utilizing substr).
• We match all numbers in preg_match_all and assign the array of matches to that key.

You might also use a pattern to match the individual parts using capturing groups and preg_replace_callback.

Pass an array by reference to the callback to set the group 1 value as the key, and an array with the values of group 2 and group 3.

([a-z]+)\[(\d+),(\d+)]

Explanation

• ([a-z]+) Capture group 1, match 1+ a char a-z
• \[ Match [
• (\d+),(\d+) Capture 1+ digits in capture group 2 and group 3 and match a , in between
• ] Match closing ]

See a regex demo and a Php demo

Example using a case insensitive match /i

$pattern = '/([a-z]+)\[(\d+),(\d+)]/i';
$str = 'Mon[3,9] Tue[3,9] Wed[5,9] Thu[5,11] Fri[5,11] Sat[5,11] Sun[4,10]';
$result = [];

preg_replace_callback(
    $pattern,
    function ($m) use (&$result) {
        $result[$m[1]] = [$m[2], $m[3]];
    },
    $str
);

print_r($result);

Output

Array
(
    [Mon] => Array
        (
            [0] => 3
            [1] => 9
        )

    [Tue] => Array
        (
            [0] => 3
            [1] => 9
        )

    [Wed] => Array
        (
            [0] => 5
            [1] => 9
        )

    [Thu] => Array
        (
            [0] => 5
            [1] => 11
        )

    [Fri] => Array
        (
            [0] => 5
            [1] => 11
        )

    [Sat] => Array
        (
            [0] => 5
            [1] => 11
        )

    [Sun] => Array
        (
            [0] => 4
            [1] => 10
        )

)

This solution converts the string to a JSON string by replacing characters. To create the desired array, only one json_decode() is necessary.

$input = 'Mon[3,9] Tue[3,9] Wed[5,9] Thu[5,11] Fri[5,11] Sat[5,11] Sun[4,10]';

$strJson = '{"'.strtr($input,[" " => ',"','[' => '":['])."}";
$array = json_decode($strJson, true);

//test output
echo "<pre>".var_export($array, true)."/<pre>";