Styled comments

<?php

// add .form-control to all woocommerce quantity inputs
add_filter('woocommerce_quantity_input_classes', function ($classes, $product) {
    $classes[] = 'form-control';
    return $classes;
}, 10, 2);

// add .form-control to variable select/input fields
add_filter('woocommerce_dropdown_variation_attribute_options_args', function ($args) {
    $args['class'] = 'form-control';
    return $args;
});

// remove url field from comment form
add_filter('comment_form_default_fields', function ($fields) {
    unset($fields['url']);
    return $fields;
});

// set comment form inputs
add_filter('comment_form_default_fields', function ($fields) {
    $fields['author'] = str_replace(
        '<input',
        '<input class="form-control" placeholder="Naam *"',
        $fields['author']
    );
    $fields['email']  = str_replace(
        '<input id="email" name="email" type="text"',
        '<input type="email" class="form-control mr-1" placeholder="Email*" id="email" name="email"',
        $fields['email']
    );

    return $fields;
});
add_filter('comment_form_defaults', function ($fields) {
    $fields['comment_field'] = str_replace(
        '<textarea',
        '<textarea class="form-control" placeholder="Vul je reactie hier in..."',
        $fields['comment_field']
    );
    return $fields;
});