woocommerce add placeholder to checkout form fields
add_filter('woocommerce_checkout_fields', 'njengah_override_checkout_fields');
function njengah_override_checkout_fields($fields)
{
unset($fields['billing']['billing_address_2']);
$fields['billing']['billing_company']['placeholder'] = 'Business Name';
$fields['billing']['billing_company']['label'] = 'Business Name';
$fields['billing']['billing_first_name']['placeholder'] = 'First Name';
$fields['shipping']['shipping_first_name']['placeholder'] = 'First Name';
$fields['shipping']['shipping_last_name']['placeholder'] = 'Last Name';
$fields['shipping']['shipping_company']['placeholder'] = 'Company Name';
$fields['billing']['billing_last_name']['placeholder'] = 'Last Name';
$fields['billing']['billing_email']['placeholder'] = 'Email Address ';
$fields['billing']['billing_phone']['placeholder'] = 'Phone ';
return $fields;
}