Return empty strings in woocommerce checkout form - forms

Question

I'd like to return empty strings on all checkout form field but one (the billing_country one).
I already know how to do it with all fields :
add_filter('woocommerce_checkout_get_value','__return_empty_string', 1, 1);
And how to do it with only one field:
add_filter('woocommerce_checkout_get_value','custom_checkout_get_value_ship_ville', 10, 2);
function custom_checkout_get_value_ship_ville( $value, $imput ){
if($imput == 'shipping_city')
$value = '';
return $value;
}
But for all but one ... I'm a little stucked.
I succeed by duplicating and adapting the previous function, but it's a lot of code for just returning empty strings.
I tried with else, elsif, switch and with logical operators, but no result.
So if someone have some clue ...
Thanks

Answer 1

If you want to return empty strings on every value of $imput except for one specific value you need to reverse the comparison of your second code snippet. So instead of comparing wether the $imput is equal to a value you compare wether the $imput is NOT equal to a value.
You can read up on this comparison here: http://php.net/manual/en/language.operators.comparison.php
You can also just return an empty string directly without assigning it to a variable:
add_filter('woocommerce_checkout_get_value','custom_checkout_get_value_ship_ville', 10, 2);
function custom_checkout_get_value_ship_ville( $value, $imput ){
if($imput != 'billing_country') {
return '';
}
}