Online PHP editor | refs for 0UFSJ

<?php function createCompressedString($shorts) { $compressLen = $compressPos = $currentLen = $currentPos = 0; $inBlock = false; for ($i = 0; $i < 8; $i++) { if ($shorts[$i] === 0) { if (!$inBlock) { $inBlock = true; $currentPos = $i; } $currentLen++; } else if ($inBlock) { if ($currentLen > $compressLen) { $compressLen = $currentLen; $compressPos = $currentPos; } $inBlock = false; $currentPos = $currentLen = 0; } } if ($inBlock) { $compressLen = $currentLen; $compressPos = $currentPos; } if ($compressLen === 8) { return '::'; } if ($compressLen > 1) { if ($compressPos === 0 || $compressPos + $compressLen === 8) { array_splice($shorts, $compressPos, $compressLen, ['', '']); } } return implode(':', array_map(function($short) { return $short === '' ? '' : dechex($short); }, $shorts)); } var_dump(createCompressedString([0, 0, 0, 0, 1, 2001, 23234, 21]));