Question

<?php
  $i == array(1, 2); 
  $j == array(a, b); 
  $m == count($j); 
  $n == count($i); 
  for ( $i = 0; $i < $m; i++ ) 
  {
    for ( $j = 0; j < $n; j++) 
    { echo $i."x"$j; }
  }
?>

The error is referencing line 6: for ( $i = 0; $i < $m; i++ )

Answer 1

for ( $i = 0; $i < $m; $i++ )

Note the dollar sign I added before the i++

Same goes for your other for statement:

for ( $j = 0; $j < $n; $j++ )

Wierd error indeed, but it i is not a variable (although PHP might flag a E_NOTICE and convert it to 'i'. You want to reference your variable, so you must add a $ before.

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Most likely what you want is:

<?php
  $iArray = array(1, 2); 
  $jArray = array('a', 'b'); 
  $n = count($iArray); 
  $m = count($jArray); 
  for ( $i = 0; $i < $n; $i++) {
    for ( $j = 0; $j < $m; $j++) { 
       echo $iArray[$i] . "x" . $jArray[$j]; 
    }
  }
?>

The things I changed:

• == is used for comparison, = is used for assignment
• The second array I assumed you wanted the string literals 'a' and 'b', but you could have also wanted $a and $b if you declared those variables somewhere else
• you assign $i to an array, but then in your for loop you overwrite it with $i = 0. You most likely want two variables
• missing $s, like I mentioned above
• $m was being used for the number of variables in $jArray, but you used it to iterate over $iArray

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So just a few pointers, brush up on you PHP and try to make sure your code works with every little change. Make 1 modification, then run it. It is very easy to get lost in syntax for PHP since it is such a dynamic scripting language