PHP array sort mutli-dimensional - php

Question

I have an array structured like so (this is the way the CSV formats it):
Array(
0 => Array(
0 => person1
1 => person2
2 => person3
//all the way to 9
),
1 => Array(
0 => id belonging to person 1
1 => id belonging to person 2
2 => id belonging to person 3
),
2 => Array(
0 => id belonging to person 1
1 => id belonging to person 2
2 => id belonging to person 3
),
//all the way to 20
)
I'm trying to sort a new array (of arrays), with each index being the value correspondent to the key in the 0 index above. i.e., person1 points to an array with all ids from the arrays 1-20 outside.
In each of the arrays after the index 0, it contains 20 ids, 0 belongs to the key 0 in the first array.
The structure I'm trying to achieve is shown below:
Array(
[person1] => Array(
id belonging to person 1
id belonging to person 1
id belonging to person 1
),
[person2] => Array(
id belonging to person 2
id belonging to person 2
id belonging to person 2
),
[person3] => Array(
id belonging to person 3
id belonging to person 3
id belonging to person 3
),
)
My attempt so far has worked, however, I had to hard code some of the indexes. What's the best solution to achieve the desired structure?

Answer 1

I'm a bit unsure if this is what you are looking for...
<?php
$arr = Array(
0 => Array(
0 => "person1",
1 => "person2",
2 => "person3"
//all the way to 9
),
1 => Array(
0 => "id belonging to person 1",
1 => "id belonging to person 2",
2 => "id belonging to person 3"
),
2 => Array(
0 => "id belonging to person 1",
1 => "id belonging to person 2",
2 => "id belonging to person 3"
)
);
foreach($arr[0] AS $id=>$name)
{
$ids[$id] = $name;
}
foreach(array_slice($arr,1) AS $persons)
{
foreach($persons AS $id=>$person)
{
// make sure to check if $ids[$id] exist and handle it as you like.
// if(isset($ids[$id]))
$people[$ids[$id]][] = $person;
}
}
print_r($people);
?>
result:
Array
(
[person1] => Array
(
[0] => id belonging to person 1
[1] => id belonging to person 1
)
[person2] => Array
(
[0] => id belonging to person 2
[1] => id belonging to person 2
)
[person3] => Array
(
[0] => id belonging to person 3
[1] => id belonging to person 3
)
)
EDIT: Should be noted I'm not making any checks on if the person's id exist in the $ids array, and neither if $people are ever set.