I'm going to show you how to use dynamic variable names in php. It's quite simple, just put your variable name in between {} symbols.

// declare prefix. In a loop this would probably be a number.
$prefix = "pfx";
 
// build your variable
${"varname_{$prefix}"}    = "success";
 
//This would output "success"
echo $varname_pfx;

Simple isn't it....