Online PHP editor | output for GA6Bg

<?php function gdr_encode($val) { // all characters that json encode without escaping $chrs = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789 !#$%&\'()*+,-.:;<=>?@[]^_`{|}~'; $base = strlen($chrs); $str = ''; while ($val > 0) { $str = $chrs[$val % $base] . $str; $val = (int)($val / $base); } return $str; } function gdr_decode($str) { // all characters that json encode without escaping $chrs = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789 !#$%&\'()*+,-.:;<=>?@[]^_`{|}~'; $base = strlen($chrs); $map = array(); for ($i=0; $i<$base; $i++) { $map[$chrs[$i]] = $i; } $val = 0; for ($i=0; $i<strlen($str); $i++) { $val *= $base; $val += (int)$map[$str[$i]]; } return $val; } $vals = array(0, 1, 99, 100, 255, 256, 999, 1000, 9999, 10000, 65535, 65536, 99999, 100000, 500000, 999999, 1000000, 4294967295, 4294967296); foreach ($vals as $val) { $enc = gdr_encode($val); $dec = gdr_decode($enc); if ($dec !== $val) { echo "ERROR: $val => $enc => $dec\n"; } else if (strlen($enc)+2 > strlen($val)) { echo "+ \"$enc\" $val\n"; } else if (strlen($enc)+2 == strlen($val)) { echo "= \"$enc\" $val\n"; } else { echo "- \"$enc\" $val\n"; } }