$ {}在php中是什么意思？

Question

I get PHP file(class) from internet and on the file doc said include file like this:

${(require_once('file.php'))}->FunctionName();

i just need to know what mean of " ${} " in this line

Answer 1

It is evaluating the contents of file.php and returning it as a string

For example - if file.php contained "test" - then it will be end up being

$test->FunctionName();

But this just seems like very bad code... evaluating a file, and including it as a variable is just going to end in tears...