Complicated PHP transpose / pivot - php

Question

I have the following array :
Array
(
[0] => Array
(
[Name] => first_data
[building] => A
[apt] => 16
)
[1] => Array
(
[Name] => first_data
[building] => B
[apt] => 16
)
[2] => Array
(
[Name] => second_data
[building] => A
[apt] => 17
)
[3] => Array
(
[Name] => second_data
[building] => B
[apt] => 18
)
and I need it to be returned as :
Array
(
[0] => Array
(
[Name] => first_data
[A] => 16
[B] => 16
)
[1] => Array
(
[Name] => second_data
[A] => 17
[B] => 18
)
Any ideas?
BTW the first array has hundreds of entries (not only first_data, but second and etc...) plus it has more than A and B.
Thanks in advance.

Answer 1

Not exactly what you want, but if you instead index the new array by the name, you can do this very easily. If the index number is some kind of ID, you can just create a field for it
foreach ( $oldarray as $index => $piece )
{
$newarray[$piece['Name']] = array($piece['building'] => $piece['apt'])
}
This will give you
Array
(
['first_data'] => Array
(
['A'] => 16,
['B'] => 16
)
['second_data'] => Array
(
['A'] => 17,
['B'] => 18
)
)
Since you have two entries with the same new, when you hit the 2nd loop, it will simply add the other building name. If you can work with this layout, then your solution is very easy, it will take more steps to do it exactly as you showed. If you absolutely have to do it the way you showed, you need extra code to loop through the new array, find the building name, add the key in the correct place, but this will be slower if you have a large amount of data.
In my opinion, the way I presented it is a far easier way to look around the array too. If you wanted to know the apt value for A in "second_data" you can just do
$newarray['second_data']['A']
with your array layout, it would require a loop to search the array for "second_data" because you have no idea where it is.