when parsing a file, PHP looks for the start and end tags, which is <?php and, which tells PHP to start and stop parsing the code between the two. This parsing allows PHP to be embedded in a variety of different documents, and any part outside the start and end tags will be ignored by the PHP parser.
PHP also allows the use of short mark < And, but not encouraged to use. Short marks can be used only by activating the Short_open_tag configuration directive in php.ini or by using the configuration option--enable-short-tags when compiling PHP.
If the file content is pure PHP code, it is best to remove the PHP end tag at the end of the file . This avoids having to accidentally add a space or line break after the PHP end tag, which causes PHP to start outputting these blanks, and there is no intention to output the script at this time.
<?php?> //Standard tags- recommended Use
<?> //Short tags, need short_open_tag-enabled in php.ini
<%%> //ASP tags, need asp_tags enabled in php.ini
<script language= "php" > </script> //script
<?phpecho "standard Mark <p>";? ><script language= "php" >echo "Scripting Style";</script>
PHP markup Style