Two-dimensional array to multidimensional array - php

Question

This is what I have:
[courses] => array
(
array([id]=>1,[name]=>"course_1",[age]=>16,[location]=>"Berlin"),
array([id]=>2,[name]=>"course_1",[age]=>18,[location]=>"Berlin"),
array([id]=>3,[name]=>"course_1",[age]=>20,[location]=>"Berlin"),
array([id]=>4,[name]=>"course_1",[age]=>16,[location]=>"London"),
array([id]=>5,[name]=>"course_1",[age]=>18,[location]=>"Rome"),
array([id]=>6,[name]=>"course_2",[age]=>16,[location]=>"Berlin")
);
What I need is to transform this into a multidimensional array like this:
- each name can have multiple ages
- each age can have multiple locations
- id is not needed
So the new transformed array should have courses that have multiple ages that have multiple locations.
I first tried to create an array for each key:
// all courses, sorted, once
$x = 0;
$course_names = array();
foreach ($courses as $item) {
$course_names[$x] = $item['name'];
$x++;
}
$course_names = array_unique($course_names);
sort($course_names);
// all ages, sorted, once
$x = 0;
$ages = array();
foreach ($courses as $item) {
$ages[$x] = $item['age'];
$x++;
}
$ages = array_unique($ages);
sort($ages);
// all locations, sorted, once
$x = 0;
$locations = array();
foreach ($courses as $item) {
$locations[$x] = $item['location'];
$x++;
}
$location = array_unique($location);
sort($location);
Then I tried to create another array as requested (don't swear at me, is one of many tries):
$counter = 0;
foreach ($location as $loc_key=>$loc_val) {
foreach ($ages as $age_key=>$age_val) {
foreach ($course_names as $cou_key=>$cou_val) {
foreach ($courses as $course) {
if ($course['name']==$cou_val) {
if ($course['age']==$age_val) {
if ($course['location']==$loc_val) {
$final_json[$counter]['ages']['locations'][] = $loc_val;
}
$final_json[$counter]['ages'][] = $age_val;
}
$final_json[$counter]['id'] = $course['id'];
$final_json[$counter]['name'] = $cou_val;
$counter++;
}
}
}
}
}
The resulted array should be something like this:
[courses] => array
(
[0] => array
(
[name] => "course_1",
[ages] => array
(
[0] => array
(
[age] => 16,
[locations] => array ([0]=>"Berlin",[1]=>"London")
),
[1] => array
(
[age] => 18,
[locations] => array ([0]=>"Berlin",[1]=>"Rome")
),
[2] => array
(
[age] => 20,
[locations] => array ([0]=>"Berlin")
)
)
)
[1] => array
(
[name] => "course_2",
[ages] => array
(
[0] => array
(
[age] => 16,
[locations] => array ([0]=>"Berlin")
)
)
)
);
I'm fighting with this for some time, I feel blocked, any idea is more than welcomed.

Answer 1

$courses = array(
array("id"=>1,"name"=>"course_1","age"=>16,"location"=>"Berlin"),
array("id"=>2,"name"=>"course_1","age"=>18,"location"=>"Berlin"),
array("id"=>3,"name"=>"course_1","age"=>20,"location"=>"Berlin"),
array("id"=>4,"name"=>"course_1","age"=>16,"location"=>"London"),
array("id"=>5,"name"=>"course_1","age"=>18,"location"=>"Rome"),
array("id"=>6,"name"=>"course_2","age"=>16,"location"=>"Berlin"),
);
foreach ($courses as $item) {
$course_age[] = $item['age'];
$course_names[] = $item['name'];
$course_location[] = $item['location'];
}
$course_age = array_unique($course_age);
$course_names = array_unique($course_names);
$course_location = array_unique($course_location);
$finalArray = array();
$finalArrayKey=0;
foreach ($course_names as $key => $courseValue) {
foreach ($courses as $key => $actualValue) {
if($actualValue['name']==$courseValue){
$finalArray[$finalArrayKey]['name'] = $courseValue;
$finalArray[$finalArrayKey]['ages'] = array();
$finalArray[$finalArrayKey]['ages']['location'] = array();
}
}
foreach ($courses as $key => $actualValue) {
if($actualValue['name']==$courseValue){
if(!in_array($actualValue['age'], $finalArray[$finalArrayKey]['ages']))
$finalArray[$finalArrayKey]['ages'][] = $actualValue['age'];
if(!in_array($actualValue['location'], $finalArray[$finalArrayKey]['ages']['location']))
$finalArray[$finalArrayKey]['ages']['location'][] = $actualValue['location'];
}
}
++$finalArrayKey;
}
echo "<pre>";
print_r($finalArray);
Sample Output:
Array
(
[0] => Array
(
[name] => course_1
[ages] => Array
(
[location] => Array
(
[0] => Berlin
[1] => London
[2] => Rome
)
[0] => 16
[1] => 18
[2] => 20
)
)
[1] => Array
(
[name] => course_2
[ages] => Array
(
[location] => Array
(
[0] => Berlin
)
[0] => 16
)
)
)

Answer 2

For simplicity sake decided to modify the output of the finalArray.
The new finalArray would look like this:
Array
(
[course_1] => Array
(
[ages] => Array
(
[16] => Array
(
[locations] => Array
(
[0] => Berlin
[1] => London
)
),
[18] => Array
(
[locations] => Array
(
[0] => Berlin
[1] => Rome
)
),
[20] => Array
(
[locations] => Array
(
[0] => Berlin
)
)
)
),
[course_2] => Array
(
[ages] => Array
(
[16] => Array
(
[locations] => Array
(
[0] => Berlin
)
)
)
)
)
This is the code:
foreach ($courses as $item) {
$course_names[] = $item['name'];
}
$course_names = array_unique($course_names);
sort($course_names);
$finalArray = array();
foreach ($course_names as $key => $courseValue) {
foreach ($courses as $key => $actualValue) {
if($actualValue['name']==$courseValue) {
$finalArray[$courseValue] = array();
$finalArray[$courseValue]['id'] = $actualValue['id'];
$finalArray[$courseValue]['ages'] = array();
}
}
foreach ($courses as $key => $actualValue) {
if($actualValue['name']==$courseValue) {
if(!array_key_exists($actualValue['age'],$finalArray[$courseValue]['ages'])) {
$finalArray[$courseValue]['ages'][$actualValue['age']] = array ();
}
}
}
}
foreach ($finalArray as $course_name=>$arr) {
foreach ($arr['ages'] as $age=>$arr2) {
foreach($courses as $item) {
if($item['name'] == $course_name && $item['age'] == $age && !in_array($item['location'], $finalArray[$course_name]['ages'][$age]['locations'])) {
$finalArray[$course_name]['ages'][$age]['locations'][] = $item['location'];
}
}
}
}

Answer 3

Not sure exactly what format you're looking for, but have a look at this:
$courses = array
(
array('id'=>1, 'name' =>"course_1",'age'=>16,'location'=>"Berlin"),
array('id'=>2,'name'=>"course_1",'age'=>18,'location'=>"Berlin"),
array('id'=>3,'name'=>"course_1",'age'=>20,'location'=>"Berlin"),
array('id'=>4,'name'=>"course_1",'age'=>16,'location'=>"London"),
array('id'=>5,'name'=>"course_1",'age'=>18,'location'=>"Rome"),
array('id'=>6,'name'=>"course_2",'age'=>16,'location'=>"Berlin")
);
$newCourses = [];
foreach ($courses as $item){
$newCourses[$item['name']]['ages'][$item['age']]['locations'][] = $item['location'];
}
$newCourses will be:
array (
'course_1' =>
array (
'ages' =>
array (
16 =>
array (
'locations' =>
array (
0 => 'Berlin',
1 => 'London',
),
),
18 =>
array (
'locations' =>
array (
0 => 'Berlin',
1 => 'Rome',
),
),
20 =>
array (
'locations' =>
array (
0 => 'Berlin',
),
),
),
),
'course_2' =>
array (
'ages' =>
array (
16 =>
array (
'locations' =>
array (
0 => 'Berlin',
),
),
),
),
)
Even if this isn't the format you're after you could probably play with it to get it how you want.