- array_map: documentation ( source)
- print_r: documentation ( source)
- explode: documentation ( source)
- trim: documentation ( source)
<?php
$xxx = "'Free', 'Include', 'Offer', 'Provide'";
$xxx_array = array_map( function( $el) { return trim( $el, "' "); }, explode(',', $xxx));
print_r( $xxx_array);