PHP delimiter <<<eof use

PHP is a web programming language, in the programming process will inevitably encounter with Echo to output a large segment of HTML and JavaScript script, if the traditional PHP output Method-by string output, There must be a large number of escapes to escape special characters such as quotes in a string to avoid syntax errors. If it is one or two can be tolerated, but if a full HTML text or a 200-line JS I think who will collapse. That's why PHP introduces a delimiter--at least for a large part of the reason.

The function of the 1.PHP delimiter is to follow the original, including the newline format, and output something inside it;
2. Any special characters in the PHP delimiter do not need to be escaped;
The PHP variable in the 3.PHP delimiter is replaced with its value as normal.

The delimiter format in PHP is this:

<<<eof
......
Eof;

Such as:

<?php$js = <<<eof<script type= "Text/javascript" >//top: The effect makes the whole frameset jump Window.top.location.href = "$group _url/manager/login"; </script>eof;echo $js;