Online PHP editor | refs for gZCA8

<?php $matches = []; $string = "#HelloWorld -> helloworld, #Hello_W0rld -> hello_w0rld, #Hello(World -> hello,"; preg_replace_callback("/#([a-z_0-9]+)/i", function($res) use(&$matches) { $matches[] = strtolower($res[1]); }, $string); var_dump($matches); $matches2 = []; $string2 = "@HelloWorld -> helloworld, @Hello_W0rl.d -> hello_w0rl,"; preg_replace_callback("/@([a-z_0-9]+)/i", function($res) use(&$matches2) { $matches2[] = strtolower($res[1]); }, $string2); var_dump($matches2);