How to create array from variable php using loop for?

Question

How to create array from variable php using loop for ?

i have many variable php like

$number_0 = 1;
$number_1 = 2;
$number_2 = 5;
$number_3 = 2;
$number_4 = 6;

i want to create array like this

$ar = array('1','2','5','2','6');

but using loop for like

for ($i=0;$i<5;$i++)
{
$number."_".$i ====> to array
}

Answer 1

Not a recomended way of doing things but:

$arr = array();
for($i=0;$i<5;$i++) {
    $varName = 'number_'.$i;
    $arr[] = $$varName;
}

Answer 2

for ($i = 1; $i <= 6; $i++)
    $ar[] = $i;

Answer 3

 for ($i=1;$i<7;$i++)
 {
      $ar[] = $i;
 }