Code-Snippets-Functions/Execute a function on a child site/WooCommerce/remove-numeric-characters-certain-billing-fields-checkout.txt

add_action( 'wp_footer', 'checkout_field_name_validator_script');
function checkout_field_name_validator_script() {
    // Only on checkout page
    if( ! ( is_checkout() && ! is_wc_endpoint_url() ) ) return;
    ?>
    <script>
    jQuery(function($){
        var b = '#billing_',    s = '#shipping_',   f = 'first_',   l = 'last_',
            n = 'name',         p = 'postcode',     c = ',';

        // Postcode fields
        $(b+p+c+s+p).bind('keyup blur',function(){
            $(this).val($(this).val().replace(/[^0-9]+/,''));
        });

        // First and Last name fields
        $(b+f+n+c+b+l+n+c+s+f+n+c+s+l+n).bind('keyup blur',function(){
            $(this).val($(this).val().replace(/[0-9.,;:?!]+/,''));
        });
    });
    </script>
    <?php
}