sprintf Example

sprintf — Return a formatted string

Example Code :

echo '<p>'.sprintf(( 'Follow <b>%s</b> on Demo!'), strip_tags($demo_account_name)).'</p>';

Joomla Code :

echo '<p>'.JTEXT::sprintf(( 'Follow <b>%s</b> on Demo!'), strip_tags($demo_account_name)).'</p>';

echo '<p>'.JTEXT::sprintf('MOD_DEMO_FOLLOW', strip_tags($snapchat_account_name)).'</p>';

In Language File you must Use in .ini file :

MOD_DEMO_FOLLOW = "Follow <b>%s</b> on Demo!"

Sample Module : AA Snapchat Snapcode Widget

Example :
https://docs.joomla.org/Formatted_fields_in_language_translation_strings