You can use some attibutes for fields. Let’s see some examples for how to use attributes.
array(
'id' => 'unique_option_101',
'type' => 'text',
'title' => 'Text Field',
'attributes' => array(
'maxlength' => 10,
'placeholder' => 'do stuff',
'readyonly' => 'only-key'
'disabled' => 'only-key'
),
),
array(
'id' => 'unique_option_102',
'type' => 'textarea',
'title' => 'Text Field',
'attributes' => array(
'rows' => 10,
'cols' => 5,
'placeholder' => 'do stuff',
),
),
array(
'id' => 'unique_option_103',
'type' => 'select',
'title' => 'Select Field',
'options' => array(
'green' => 'Green',
'blue' => 'Blue',
'yellow' => 'Yellow',
),
'attributes' => array(
'multiple' => 'multiple',
'style' => 'width: 125px; height: 125px;',
),
),