Powerful Meta Keyword Wordpress

//Get title > remove symbolic character > add comma before space > set to Powerful Meta Keyword (Wordpress Official By L3n4r0x)

<meta name="keywords" content="<?php $string = get_the_title(); //Mengambil Judul Post
$f = preg_replace('/[^\p{L}\p{N}\s]/u', '', $string); //Menghapus Symbol dan huruf Spesial
$c = preg_replace('#\s+#', ', ',trim($f)); //Menambah koma sebelum spasi
echo $c; //Menampilkan Hasil ?>">