You can use the **[`wp_trim_excerpt()`](http://codex.wordpress.org/Function_Reference/wp_trim_excerpt)** to get the excerpt of the content.

You can use it inside your loop to get the excerpt of each post

> the string provided to a maximum of 55 words if it is more then a [...] will be added to the end of the string.


    <?php
        $recent_posts = wp_get_recent_posts(array('post_type'=>'jokes'));
        foreach( $recent_posts as $recent ){
            echo '<li><a href="' . get_permalink($recent["ID"]) . '" title="Look '.esc_attr($recent["post_title"]).'" >' .   $recent["post_title"].'</a> </li> ';
            $excerpt = wp_trim_excerpt( $recent['post_content']); // $excerpt contains the excerpt of the concerned post
            echo $excerpt;
        }
    ?>