PHP structure, syntax

·         All the php code in a php script enclosed within <?Php and ?> (Canonical PHP Tags).
·         Adding php code inside the PHP tags is known as Escaping to php
Short-open (SGML-style) tags
<?Php  ...   ?>
Or
<?  ...   ?>
Or
In the HTML script tags, (for adding javascript code in HTML document)
<script language="PHP">  ...   </script>
 
·         Every expression in PHP ends with a semicolon ;
·         The default file extension of PHP files is ".php".
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