Php和宏（lisp风格）？

Question

Hi im learning LISP and well, all day i program php for a living, so i was messing around with php.net and found the eval function... so i started playing around!

I would love to know more about how to use eval to do crazy stuff, i know you can make functions with this and everything... but i wanted to ask why the next code wont work:

$var = "echo \"FOZZ\";";
for($i = 0; $i < 100; $i++)
    $var  = "eval(\"".$var."\");";
print $var;   
eval($var);

Also what other stuff is interesting with eval!

Answer 1

Your statement comes out to 'eval("eval("echo"FOZZ";");")'. Your double quotes are interfering with each other and causing the error.

You might want to try changin the first line to $var = "echo \'FOZZ\';";

Note: Please be careful using eval.