Online PHP editor | refs for rkXLt

<?php function do_split($name) { return preg_split('/([A-Z]{2,}|([A-Z][^A-Z]*))/', $name, null, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY); } function convert_case($name) { return implode( '_', array_map( 'strtolower', do_split($name) ) ); } function convert_case2($in) { $len = strlen($in); if ($len < 2) { return strtolower($in); } $pos = 0; $out = ''; $peek = function() { if ($pos+1 >= $len) { return null; } return $in[$pos+1]; }; $upper = function ($c) { return 'A' <= $c && $c <= 'Z'; }; $lower = function ($c) { return 'a' <= $c && $c <= 'z'; }; $alpha = function ($c) use ($upper, $lower) { return $upper($c) || $lower($c); }; $num = function ($c) { return '0' <= $c && $c <= '9'; }; $alpha_num = function ($c) use ($alpha, $num) { return $alpha($c) || $num($c); }; $start_state = function () { return null; }; $state = $start_state; while ($state !== null) { $state = $state(); } return strtolower($output); } convert_case2('FooBARbar0123'); $samples = array( 'FooBar', 'FooBAR', 'FOOBar', 'foo_bar', 'FOO_bar', 'FOO_Bar', 'foo_BAR', 'foo_Bar', 'Foo_bar', ); print_r(array_map(function ($name) { return array( 'name' => $name, 'converted' => convert_case2($name), // 'converted' => convert_case($name), ); }, $samples));