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<?php $cards = [ [ "from" => "Barcelona", "to" => "Gerona Airport", ], [ "from" => "Stockholm", "to" => "New York JFK", ], [ "from" => "Gerona Airport", "to" => "Stockholm", ], [ "from" => "New York JFK", "to" => "Amsterdam", ], [ "from" => "Amsterdam", "to" => "London", ], [ "from" => "Madrid", "to" => "Barcelona", ] ]; $result = []; function doSort($cards, &$result, $start = "Madrid") { foreach ($cards as $key => $card) { if ($card["from"] === $start) { $result[] = $card; doSort($cards, $result, $card["to"]); } } } doSort($cards, $result); print_r($result);
Output for 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.28, 8.4.1 - 8.4.14, 8.5.0
Array ( [0] => Array ( [from] => Madrid [to] => Barcelona ) [1] => Array ( [from] => Barcelona [to] => Gerona Airport ) [2] => Array ( [from] => Gerona Airport [to] => Stockholm ) [3] => Array ( [from] => Stockholm [to] => New York JFK ) [4] => Array ( [from] => New York JFK [to] => Amsterdam ) [5] => Array ( [from] => Amsterdam [to] => London ) )
Output for 8.4.15
/bin/php-8.4.15: /usr/lib/libm.so.6: version `GLIBC_2.38' not found (required by /bin/php-8.4.15) /bin/php-8.4.15: /usr/lib/libm.so.6: version `GLIBC_2.35' not found (required by /bin/php-8.4.15) /bin/php-8.4.15: /usr/lib/libc.so.6: version `GLIBC_2.34' not found (required by /bin/php-8.4.15) /bin/php-8.4.15: /usr/lib/libc.so.6: version `GLIBC_2.38' not found (required by /bin/php-8.4.15)
Process exited with code 1.

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