3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?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($name) ) ); } function convert_case2($name) { $output = ''; for ($i=0; $i<strlen($name); $i++) { $char = $name[$i]; print_r("{$char} " . json_encode(ctype_upper($char))); } return strtolower($output); } convert_case2('FooBARbar'); $samples = array( 'FooBar', 'FooBAR', 'FOObar', 'foo_bar', 'FOO_bar', 'foo_BAR', 'foo_Bar', 'Foo_bar', ); /* print_r(array_map(function ($name) { return array( 'name' => $name, 'split' => do_split($name), 'converted' => convert_case($name), ); }, $samples)); */
based on LKRMg
Output for 5.2.0 - 5.6.28, hhvm-3.10.0 - 3.12.0, 7.0.0 - 7.1.0
F trueo falseo falseB trueA trueR trueb falsea falser false
Output for 5.0.0 - 5.1.6
Fatal error: Call to undefined function json_encode() in /in/qPNjh on line 21
Process exited with code 255.
Output for 4.4.5 - 4.4.9
Fatal error: Call to undefined function: json_encode() in /in/qPNjh on line 21
Process exited with code 255.
Output for 4.3.2 - 4.4.4
Fatal error: Call to undefined function: json_encode() in /in/qPNjh on line 21
Process exited with code 255.
Output for 4.3.0 - 4.3.1
Fatal error: Call to undefined function: json_encode() in /in/qPNjh on line 21