nested foreach in PHP problem

Question

I'm having problems to iterate twice on the same array:

<? $indice=0 ?>
<?php foreach ($comisiones as $comision1):?>  
  <tr>  
    <td><?php echo ++$indice ?></td>  
    <td><?php echo tag('select',array('name'=>'comision_'.$indice),true)?>  
          <?php foreach ($comisiones as $comision2):?>  
            <option value="<?php echo $comision2->getId()?>">
               <?php echo $comision2->getNombre()." - ".$comision2->getDescripcion()?> 
            </option>
          <?php endforeach?> 
        </select>
    </td>
  </tr>
<?php endforeach?>  

The above code prints:

And I'm expecting to see something like this (labels of the combos in the images are not the same, but I think the idea is clear):

Thanks in advance

Answer 1

My first instict is don't use foreach loops. I believe that PHP is using some internal pointers so the two foreach loops affect each other's position. Instead use a normal for loop.

Answer 2

Based on your code it seems like you don't actually want a foreach loop in the outher loop. Just do a regular for loop from 0 to the size of the array. Something like this:

for ($i = 0; $i < count($comisiones); ++$i) {
    // Do what you want
}

Answer 3

I belive thet the second loop should looks like or its related to

<?php foreach ($comision1 as $comision2): ?>

not

<?php foreach ($comisiones as $comision2): ?>  

otherwise you are not using $commision1 from first loop anyware

<?php foreach ($comisiones as $comision1): ?>  

Answer 4

Use normal for loops with two indexes, like this:

$len = count($comisiones);
for($i = 0; $i < $len; ++$i)
   for($j = 0; $j < $len; ++$j)

As stated clearly on PHP website:

"Note: When foreach first starts executing, the internal array pointer is automatically reset to the first element of the array." [source: http://www.php.net/manual/en/control-structures.foreach.php ]

Therefor your inner foreach loop resets every time the array pointer, that's why you are getting out only a terrible mess. :)

Answer 5

I had a similar interesting prob with foreach in an foreach but with not the same Arrays...

Had a Zend MVC, with the controller fetching results fron two tables into two view-variables:

$foodTable = new Table_Food();
$foodTable->select()->where(array('active' => true));

$foodCategoryTable = new Table_FoodCategory();
$foodCategoryTable->select()->order(array('order'));

$food = $foodTable->fetchAll();
$foodCategories = $foodCategoryTable->fetchAll();

$this->view->food = $food;;
$this->view->foodCategories = $foodCategories;

Then the view made two loops, first over the categories and inside over the food, which has everyone a category. If the category-id of the food loop is the category-id of the category loop -> print it to screen...

<?php foreach($this->foodCategories as $foodCategoryKey => $foodCategory) { ?>
  // echo the category header
    <?php foreach($this->food as $foodKey => $food) {
      if($food["food_category_id"] == $foodCategory["id"]){ ?>
        // echo food, food details, price, and so on
      <? }
    }
} ?>

In this version the array-key of the outher loop did not loop from 0 to 5 (like this: 0, 1, 2, 3, 4, 5), but form 0 to 4 (in this way: 0, 2, 4) and said: "I've done it, baby". I had 6 categories (0-Insalate, 1-Pizza, 2-Pasta, 3-Secondi Piati, 4-Desserts, 5-Drinks) and on the screen i got no Pizza, no Secondi piati and no Drinks...

The "step" of the outer loop (known from other programming languages) was 2, not 1 like expected.

I ran out of energy searching for the "why".

Different tables, different variables, different foreach-loops and foreach-params and so on... I tried many things, but always the "step 2" in outer foreach.

The inner loop, printing the food details, always worked normal.

Tried to replace the outher foreach with

for($foodCategoryKey = 0; $foodCategoryKey < count($this->foodCategories); $foodCategoryKey++) { ... }

and everything worked fine.

But not with foreach...

Why, why, why ???

Since I changed the variable-assignment in the controller to:

$this->view->food = $food->toArray();
$this->view->foodCategories = $foodCategories->toArray();

it worked like it should - like the for() - loop ...

Can anybody tell me where the devil in Mrs. Jones is here?

Yours,

Walta