WP Content with Read More

function read_more_content(){
$string = get_the_content();
$hiddstring = get_the_content();	
   if (strlen($string) > 120) {
       $string = substr($string, 0, 114);// change 15 top what ever text length you want to show.
       // $endPoint = strrpos($stringCut, ' ');
       // $string = $endPoint? substr($stringCut, 0, $endPoint):substr($stringCut, 0);
    $string .= '<span class="hidden_box">'.substr($hiddstring, 114).'</span>';
     $string .= '<a href="javascript:void(0)" class="read_more">...Read More</a>';
   }
   echo $string;	
}

<?php read_more_content();?>

jQuery(document).on('click', '.read_more', function(e) {
      jQuery(this).toggleClass("open");
      jQuery('.read_more.open').html('Read Less');
    jQuery('.read_more:not(.open)').html('...Read More');
      jQuery(this).prev('.hidden_box').toggleClass("show");
   });

.hidden_box {
    transition: all 2s linear;
    display: none;
}
 .hidden_box.show {
    display: inline;
}