<?php
class my_test_Widget extends WP_Widget {

    public function __construct() {
        parent::__construct(
            'my_test_widget', // Base ID
            'my test Widget', // Name
            array( 'description' => 'This is a test widget.')
        );
    }

public function widget( $args, $instance ) {

    $title = apply_filters( 'widget_title', $instance['title'] );
    $textarea = apply_filters( 'widget_textarea', empty( $instance['textarea'] ) ? '' : $instance['textarea'], $instance );

        echo $args['before_widget'];

        echo'<div id="my-test" class="text-center">';
    if ( !empty( $textarea ) ) {
    echo'<div class="page-caption text-center"><h3>' . $textarea . '</h3></div>';
    }
        echo'</div>';

        echo $args['after_widget'];
}

    public function form( $instance ) {

        $title = ! empty( $instance['title'] ) ? $instance['title'] : '';
        $textarea = ! empty( $instance['textarea'] ) ? $instance['textarea'] : '';

        ?>
        <p>
            <label for="<?php echo $this->get_field_id( 'title' ); ?>">Title:</label>
            <input class="widefat" id="<?php echo $this->get_field_id( 'title' ); ?>" name="<?php echo $this->get_field_name( 'title' ); ?>" type="text" value="<?php echo esc_attr( $title ); ?>">
        </p>
            <p>
            <label for="<?php echo $this->get_field_id( 'textarea' ); ?>">Textarea:</label>
            <textarea class="widefat" id="<?php echo $this->get_field_id( 'textarea' ); ?>" name="<?php echo $this->get_field_name( 'textarea' ); ?>" rows="10" cols="20" value="<?php echo $textarea; ?>"></textarea>
        </p>

    <?php
    }

    public function update( $new_instance, $old_instance ) {
        $instance = array();
        $instance['title']       = ( !empty( $new_instance['title'] ) ) ? strip_tags( $new_instance['title'] ) : '';
            $instance['textarea']     = ( !empty( $new_instance['textarea'] ) ) ? strip_tags( $new_instance['textarea'] ) : '';

        return $instance;
    }
}

add_action( 'widgets_init', function(){
     register_widget( 'my_test_Widget' );
});

?>