Automatically add a Google+ button to your posts

Open your functions.php file and paste the following code in it:

<?php  
add_filter('the_content', 'wpr_google_plusone');
 function wpr_google_plusone($content) {
      $content = $content.'<div class="plusone"><g:plusone size="tall" href="'.get_permalink().'"></g:plusone></div>';  
    return $content; 
 } 
 add_action ('wp_enqueue_scripts','wpr_google_plusone_script'); 
 function wpr_google_plusone_script() {  
    wp_enqueue_script('google-plusone', 'https://apis.google.com/js/plusone.js', array(), null);  }
 ?>