How to combine associative array by indexes [duplicate] - php

Question

This question already has answers here:
Transposing multidimensional arrays in PHP
(12 answers)
Closed 10 months ago.
I have this associative array below:
Array
(
[0] => Array
(
[0] => Category
[1] => fruit
[2] => carbs
)
[1] => Array
(
[0] => Day 1 - Program
[1] => Eat banana
[2] => Eat bread
)
[2] => Array
(
[0] => Day 1 - record
[1] =>
[2] =>
)
)
each array index relates to the same index in the other arrays.
I need to now create 3 arrays by combining the index. The finished array would
look like this:
Array
(
[0] => Array
(
[0] => Category
[1] => Day 1 - Program
[2] => Day 1 - record
)
[1] => Array
(
[0] => fruit
[1] => Eat banana
[2] =>
)
[2] => Array
(
[0] => carbs
[1] => bread
[2] =>
)
)
The empty slots are where I know to put a textbox to record the data.
I've tried nesting for loops and other things but nothing is working.
How to combine array into a multidimensional array based on indexes?

Answer 1

$output = call_user_func_array(
'array_map',
array_merge(
array(NULL),
$input
)
);
Demo

Answer 2

You can achieve this with a nested loop. Loop through the sub-arrays first. On each iteration, loop through the elements in the sub-array, and add them into the result array. The important part here is what we use as the index for the $result array. $index will be the position of the array element in the sub-array. For example, Category would have an index of 0, so it would be pushed to $result[0][].
foreach ($array as $sub) {
foreach ($sub as $index => $val) {
$result[$index][] = $val;
}
}
print_r($result);
Demo

Answer 3

Here's a quick way - it essentially flips the keys. BTW, the first array you have is an indexed array, not an associative array.
$input = array(
array
(
"Category", "fruit", "carbs"
),
array
(
"Day 1 - Program","Eat banana","Eat bread"
),
array
(
"Day 1 - record", "", ""
)
);
foreach ($input as $key => $array){
foreach ($array as $k => $v){
$output[$k][$key] = $input[$key][$k];
}
}
print_r($output);