使用连接在循环内声明PHP变量

I need to make PHP variables all starting with $hex followed by numbers 1-8.

In a loop, can I concatenate the increment, i, with the variable, like this:

$hex . i

Or will that not work?

EDIT: never mind, I figured it out: ${ }

Maybe you could use eval php function:

eval('$hex'. $i . ';');