PHP: For Loops

print "<table>";
for ($y=1; $y<= 12 ; $y++) {
print "<tr>\n";
 for ($x=1; $x<= 12 ; $x++) {
  if ($x==$y) {print "<td bgcolor=red>\n";}
  else {print "<td>\n";}   
  print ($x * $y);
  print "</td>\n";
       }
print "</tr>\n";
       }
print "</table>";

1	2	3	4	5	6	7	8	9	10	11	12
2	4	6	8	10	12	14	16	18	20	22	24
3	6	9	12	15	18	21	24	27	30	33	36
4	8	12	16	20	24	28	32	36	40	44	48
5	10	15	20	25	30	35	40	45	50	55	60
6	12	18	24	30	36	42	48	54	60	66	72
7	14	21	28	35	42	49	56	63	70	77	84
8	16	24	32	40	48	56	64	72	80	88	96
9	18	27	36	45	54	63	72	81	90	99	108
10	20	30	40	50	60	70	80	90	100	110	120
11	22	33	44	55	66	77	88	99	110	121	132
12	24	36	48	60	72	84	96	108	120	132	144

Lesson: Quantity of "For Loops" = "Amount of Dimensions".

Almost same program on command line:

<?php for ($y=1; $y<= 12 ; $y++) { echo "\n";     for ($x=1; $x<= 12 ; $x++) {         echo "\t";                     echo ($x * $y);                    } echo "\n";              } ?>

Just copy that into a file named numbers.php, and run it by this command:
php ./numbers.php