<?php
$var_name = 'Any string..☺..ж..╚ can be a variable name';
$$var_name = 'test -- by variable variable';
$' ' = 'test -- by quoted string as variable name';
var_dump($GLOBALS);
Parse error: syntax error, unexpected '' '' (T_CONSTANT_ENCAPSED_STRING), expecting variable (T_VARIABLE) or '$' in /in/pi6bQ on line 8
Process exited with code 255.