Static Variable and Default Argument Initializers Accept Only Scalar Values

Static Variable and Default Argument Initializers Accept Only Scalar Values

That means the values of these initializers must be known at compilation time; that is, they cannot be an expression.

Valid in PHP 3

 <?php $variable = "GLOBALS"; function print_array ($varname = $variable) {     global $$varname;     reset ($$varname);     while (list ($na, $val) = each ($$varname))         print "$na: $val"; } ?> 

Valid in PHP 4

 <?php function print_array ($varname = "GLOBALS") {     global $$varname;     reset ($$varname);     while (list ($na, $val) = each ($$varname))         print "$na, $val\ n<br>\n"; } ?>