php - How to add different and common classes in radioList() in yii2

The below code should work for you.

<?php echo $form->field($model, 'customer_sel')->radioList(
        [
            'customer' => 'Customer',
            'supplier' => 'Supplier',
            'excludecustomer' => 'Exclude Customer',
            'all' => 'All',
        ],
        [
            'item' => function ($index, $label, $name, $checked, $value) {

                $return = '<label>';
                $return .= '<input class="inputbox inputindex_' . (++$index) . '" type="radio" name="' . $name . '" value="' . $value . '" ' . ($checked ? "checked" : "") . '>';
                $return .= ucwords($label);
                $return .= '</label>';
                return $return;
            },

        ]
    )->label('Select Choice');
?>

Note: to make the first option selected by default, you should set the attribute with the value inside the action. like

$model = new CashBankentry();
$model->customer_sel='customer';

Solution:

I think it will be easier if you generate the markup without using the $form->field() helper. Check its implementation and you will see the different parts you need to code by separate.

A call to $form->field() basically calls to Html::activeLabel() Html::activeInput() and Html::activeError()