[PHP] Variable with name of other variable – “variable variables”

admin — Tue, 02 Sep 2008 16:50:13 +0000

When you write in PHP $$name, parser treats it as variable, wchich name is value of $name – it works like pointer:

 
$var1 = 'test1';
$var2 = 'test2';
$a = 'var1';
echo $$a.'
';
$a = 'var2';
echo $$a;
?>

output:

test1
test2

[PHP] Execution/evaluation of code from variable

admin — Tue, 02 Sep 2008 13:26:15 +0000

In PHP we can use function eval in order to evaluate given variable (string) as PHP code:

 
$var = 'for ($i=0;$i<5;$i++)
{
	echo $i.\'
\';
}';
eval($var);
?>

output: