Sep 2

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

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 $$a.'<br>';
$a = 'var2';
echo $$a;
?>

output:

test1
test2

Sep 2

[PHP] Execution/evaluation of code from variable

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 $i.\'<br>\';
}';
eval($var);
?>

output: