add_action('wp_head',..);

function add_brand_style($newItem){
    global $newItem;
    echo 'item:'.$newItem;
}
add_action('wp_head','add_brand_style');

$array = array("keywords" => "keywords here", "description" => "desc here");
add_action( 'wp_head', function() use ( $array ) {
    foreach ($array as $key => $value) {
        if ($key == "description") { echo "your meta here"; }
    }
}, 1 );