Proper Syntax for PHP foreach function with associative arrays - php

Question

I have the following array named $ingredient_difference in PHP (example output below):
Array (
[total_remaining_ingredients] => Array (
[0] => 2 [1] => 3 [2] => 10
)
[idrecipe] => Array (
[0] => 8 [1] => 10 [2] => 9
)
[value] => Array ( [0] => 1 [1] => 1 [2] => 1 )
)
I'm trying to extract at least the values of idrecipe using 'foreach', but I'm getting undefined index with the following code:
foreach($ingredient_difference as $recipe_output)
{
echo $recipe_output['idrecipe']."<br />";
}
I know the above isn't exactly the way to do it, but this also was not working (undefined index error for 'idrecipe', 'value' and 'total_remaining_ingredients'):
foreach($ingredient_difference as $c => $rowkey)
{
$sorted_idrecipe[] = $rowkey['idrecipe'];
$sorted_value[] = $rowkey['value'];
$sorted_remaining_ingredients[] = $rowkey['total_remaining_ingredients'];
}
What am I missing in my foreach syntax? Or is there a better way?
This foreach construct is also giving undefined index errors:
foreach($ingredient_difference as $rowkey => $index_value)
{
$id_value[$key] = $index_value['idrecipe'];
$value_value[$key] = $index_value['value'];
$tri_value[$key] = $index_value['total_remaining_ingredients'];
}
Answer thanks to ComFreek:
$result_ingredient_difference = array();
$count_id = count($ingredient_difference['idrecipe']);
for ($i=0; $i<$count_id; $i++)
{
$result_ingredient_difference[] = array(
'tri' => $ingredient_difference['total_remaining_ingredients'][$i],
'idrecipe' => $ingredient_difference['idrecipe'][$i],
'value' => $ingredient_difference['value'][$i]
);
}
//rearranged array of $result_ingredient_difference able to call proper indexing with the below
foreach($result_ingredient_difference as $rowkey => $index_value)
{
$id_value[$key] = $index_value['idrecipe'];
$value_value[$key] = $index_value['value'];
$tri_value[$key] = $index_value['tri'];
}

Answer 1

With your first foreach() loop, you iterate over the main array and not over the values of the subarray idrecipe!
foreach($ingredient_difference['idrecipe'] as $value)
{
echo $value;
}

Answer 2

foreach constructs a loop. In your code
foreach($ingredient_difference as $recipe_output) {
echo $recipe_output['idrecipe']."<br />"; }
in the first loop run: $recipe_output is $ingredient_difference[total_remaining_ingredients]
in the second loop run: $recipe_output is $ingredient_difference[idrecipe]
in the third loop run: $recipe_output is $ingredient_difference[value]
because there is no
$ingredient_difference['total_remaining_ingredients']['idrecipe']
$ingredient_difference['idrecipe']['idrecipe']
$ingredient_difference['value']['idrecipe']
you get the error.
to see how the foreach loop works use the examples on http://php.net/manual/de/control-structures.foreach.php
i Expect what you want to do is:
foreach($ingredient_difference['idrecipe'] as $value_of_recipe)
{
echo $value_of_recipe."<br />";
}