Use Multidimensional Array within a For Loop in PHP

Question

I have the following multidimensional array:

<? $array = array(0 => 2, 3 => 1, 5 => 1 );

Which looks like this when printed:

Array ( [0] => 2 [3] => 1 [5] => 1 );  //the value in brackets is the shoe size

The first part of array is a "shoe size", and the second part of the array is the number available in inventory.

I am trying to print out a table that lists all shoe sizes (even if not in the array), and then loop through to provide "number available" in inventory.

Here's what I have so far, but isn't working:

<?php
   $array = array(0 => 2, 3 => 1, 5 => 1 );
   print ('<table>');
    print ('<thead><tr><th>Shoe Size</th>');
    for ($i=3; $i<=12; $i += .50) {
               print ('<th>'.$i.'</th>');
            }
    print('</tr></thead>');
    print('<tbody><td>Total</td>');
    foreach ($array as $shoe_size=>$number_in_inventory) { 
        for ($i=3; $i<=12; $i += .50) {
            if ($i == $shoe_size) {
                print('<td>'.$number_in_inventory.'</td>'); 
            }
            else {
                print('<td>0</td>');
            }
        }
    }
    print("</tbody></table>");

My problem is, because I have a foreach loop AND a for loop, it is printing out twice the number of table columns (<td>'s).

How can I better adjust this code so that it only loops through and correctly displays the columns once? I am pretty lost on this one.

Many thanks!

salathe · Accepted Answer · 2011-03-18 07:45:30Z

2

Change your main loop to go through each possible shoe size; if the size exists in the inventory array ($array) then print that value, else print zero.

// ...
print('<tbody><td>Total</td>');
for ($i = 3; $i <= 12; $i += .50) {
    if (array_key_exists("$i", $array)) {
        print '<td>'.$array["$i"].'</td>'; 
    } else {
        print '<td>0</td>';
    }
}
// ...

My problem is, because I have a foreach loop AND a for loop, it is printing out twice the number of table columns ('s).

That is precisely the problem. Just like with the <th> section, you want to print a <td> for each of the possible shoe sizes (3 through 12). For each possible shoe size, all you need to do is check to see whether there is a corresponding value in the inventory as my snippet above does.

edited Mar 18, 2011 at 7:45

answered Mar 17, 2011 at 19:59

salathe

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2 Comments

Dodinas Over a year ago

Thanks for the reply. I got the following PHP warning: The first argument should be either a string or an integer, so I tried changing it to: if (array_key_exists('$i', $array)) {, but now it just displays all zeros. Any idea on what's causing this?

salathe Over a year ago

The problem is that you'll be mixing integer (whole number) and string (for the half-sizes) array keys. As for what's causing your specific problem, you're using single-quotes where you don't want to. Note that arrays cannot have float (e.g. 0.5) values as keys.

fredrover · Accepted Answer · 2011-03-17 19:57:43Z

0

You might try looping through all the sizes and then for each size, check to see if it's in the array using array_key_exists()

answered Mar 17, 2011 at 19:57

fredrover

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