src/View/Loop.php
public function thumbnailUrl($size = null, $icon = false)
    {
        $data = wp_get_attachment_image_src(get_post_thumbnail_id($this->id()), $size, $icon);

        return (empty($data)) ? null : $data[0];
    }
public function thumbnailUrl($size = null, $icon = false)
    {
        $data = wp_get_attachment_image_src(get_post_thumbnail_id($this->id()), $size, $icon);

        return (empty($data)) ? null : $data[0];
    }
public function thumbnailUrl ( $ size = null , $ icon = false ) { $ data = wp_get_attachment_image_src ( get_post_thumbnail_id ( $ this -> id ( ) ) , $ size , $ icon ) ; return ( empty ( $ data ) ) ? null : $ data [ 0 ] ; }
Get thumbnail url of current post.

@param string|array $size The size of the current post thumbnail.
@param bool         $icon

@return null|string
Get thumbnail url of current post .