How to Limited Char show for post title and post content

add_filter( 'the_title', 'wpse_75691_trim_words' );

function wpse_75691_trim_words( $title )
{
     return mb_strimwidth($title, 0, 20, '...');
}

add_filter( 'the_excerpt', 'content_trim_words' );

function content_trim_words( $content )
{
   return mb_strimwidth($content, 0, 80, '...');
}