php loop array and update - php

Question

I have an array and I wish to update the values in roomTotalPrice. However when I loop, it changes to just a variable.
Array I want to change:
Array
(
[10] => Array
(
[12] => Array
(
[num_rooms] => 2
[adults] => Array
(
[0] => 2
[1] => 2
)
[prices] => Array
(
[0] => 44.5
[1] => 44.5
)
[roomTotalPrice] => Array
(
[0] => 44.5
[1] => 44.5
)
[price] => 178
[supp] => 0
)
)
Code I am using:
//Total Room Price
foreach($iroom['roomTotalPrice'] as $irt){
$s_rate[$iraid][$iroid]['roomTotalPrice'] = 100;
}
Array
(
[10] => Array
(
[12] => Array
(
[num_rooms] => 2
[adults] => Array
(
[0] => 2
[1] => 2
)
[prices] => Array
(
[0] => 44.5
[1] => 44.5
)
[roomTotalPrice] => 100
[price] => 178
[supp] => 0
)
)

Answer 1

Use this code:
foreach($iroom['roomTotalPrice'] as &$irt){
$irt = 100;
}
Anyway this code is based on the fact that $iroom['roomTotalPrice'] loop on the right sub-array as you have written.

Answer 2

Are you trying to make the sum for prices ?
$x[10][12][roomTotalPrice] = array_sum($x[10][12][roomTotalPrice])

Answer 3

Assuming that the $iroom variable is the array in your first code sample, I believe you can use the following code to set all 'roomTotalPrice' entries to 100:
foreach ($iroom as $firstLevelIndex => $firstLevelArray) {
foreach ($firstLevelArray as $secondLevelIndex => $secondLevelArray) {
$iroom[$firstLevelIndex][$secondLevelIndex]['roomTotalPrice'] = 100;
}
}

Answer 4

Is this what your want?
foreach ($iroom as $k1 => $v1) { // Loop outer array
foreach ($v1 as $k2 => $v2) if (isset($v2['roomTotalPrice'])) { // Loop inner arrays and make sure they have a roomTotalPrice key
foreach ($v2['roomTotalPrice'] as $k3 => $v3) { // Loop roomTotalPrice array
$iroom[$k1][$k2]['roomTotalPrice'][$k3] = 100; // Change the values
}
}
}