Thread: remove filter excerpt_length

remove filter excerpt_length

trying to upgrade the length of characters for blog post excerpt
found that function but did n t work for me

what are those 2 values referring too?
after_setup_theme
vantage_child_setup

---

add_action( 'after_setup_theme', 'vantage_child_setup' );
function vantage_child_setup(){
remove_filter( 'excerpt_length', 'va_excerpt_length' );
add_filter( 'excerpt_length', 'va_child_excerpt_length' );
}
function va_child_excerpt_length() {
return 200;
}