Recursive function for a multidimensional array? - php

Question

I am attempting to use a recursive function to search through a multidimensional array, such as the one below, to find certain values, i.e. people who went to certain school, majored in a certain subject, hold a certain job title, etc. In case your wondering, this array is output from the Facebook Graph API. In reality there are more than 3 offset arrays, depending on the number of friends a user has, it could be in the thousands.
Here's a solution I tried with very little knowledge of recursive functions (my first thought was to use in_array before I found out it didn't work for md arrays):
So to give you an idea of how the md array below works, check out this snippet of code:
$friend = $fqlResult[0]['name'];
echo "$friend";
*The output would be "BLANK" since I deleted the person's name.
$data = $fqlResult;
$collegemajor = (isset($value['education'][0]['concentration'][0]['name'])) ? $value['education'][0]['concentration'][0]['name'] : null ;
$major = "Business Administration";
if (isset($collegemajor)) {
foreach($data as $key=> $value) {
if ($value($collegemajor) == $major) {
echo "User $key is majoring in $major";
}
}
}
So here is the multidimensional array referenced above. In this example, I want to pull the names of all of the user's friends who majored in Business Admin. in college. As you can see from this snippet, there aren't any (I think) but in the long version of the array, there are plenty. The code above produces no output and I'm lost as to how to make it work. Any help would be greatly appreciated.
Array
(
[0] => Array
(
[name] => BLANK
[education] =>
[work] =>
)
[1] => Array
(
[name] => BLANK
[education] => Array
(
[0] => Array
(
[school] => Array
(
[id] => 108087985890571
[name] => St. Andrew's School
)
[year] => Array
(
[id] => 138383069535219
[name] => 2005
)
[type] => High School
)
[1] => Array
(
[school] => Array
(
[id] => 20697868961
[name] => Boston University
)
[concentration] => Array
(
[0] => Array
(
[id] => 108654845832522
[name] => Business Administration
)
)
[type] => College
)
[2] => Array
(
[school] => Array
(
[id] => 108289315859633
[name] => University of Miami
)
[year] => Array
(
[id] => 138879996141011
[name] => 2013
)
[type] => Graduate School
)
)
[work] => Array
(
)
)
[2] => Array
(
[name] => BLANK
[education] => Array
(
[0] => Array
(
[school] => Array
(
[id] => 115444241803885
[name] => Saint Andrews High School
)
[year] => Array
(
[id] => 137616982934053
[name] => 2006
)
[type] => High School
)
[1] => Array
(
[school] => Array
(
[id] => 112033702149888
[name] => Boca Raton High
)
[year] => Array
(
[id] => 137616982934053
[name] => 2006
)
[type] => High School
)
[2] => Array
(
[school] => Array
(
[id] => 108087985890571
[name] => St. Andrew's School
)
[type] => High School
)
[3] => Array
(
[school] => Array
(
[id] => 107573562605861
[name] => Duke University
)
[concentration] => Array
(
[0] => Array
(
[id] => 104045469631213
[name] => Political science
)
)
[type] => College
)
)
[work] =>
)
[4] => Array
(
[uid] => 1234567
[name] => BOB NO ONE
[education] => Array
(
[0] => Array
(
[school] => Array
(
[id] => 106039752760627
[name] => Berwick Academy
)
[year] => Array
(
[id] => 137616982934053
[name] => 2006
)
[type] => High School
)
[1] => Array
(
[school] => Array
(
[id] => 108087985890571
[name] => St. Andrew's School
)
[type] => High School
)
[2] => Array
(
[school] => Array
(
[id] => 105690226130720
[name] => Northeastern University
)
[concentration] => Array
(
[0] => Array
(
[id] => 108654845832522
[name] => Business Administration
)
)
[type] => College
[classes] => Array
(
[0] => Array
(
[id] => 189873264368867
[name] => 2011
)
)
)
)

Answer 1

There's really no need for recursion for something like this, considering the depth of the tree is always fixed and the structure is known. Using some nested loops would do the trick:
$friends = $fqlResult;
$friends_BA = array();
foreach ($friends as $friend) {
if (is_array($friend['education'])) {
foreach ($friend['education'] as $school) {
if (isset($school['concentration'])) {
foreach ($school['concentration'] as $concentration) {
if (strpos(strtolower($concentration['name']), 'business') !== false) {
$friends_BA[] = $friend;
continue 3; // skip to the next friend
}
}
}
}
}
}
var_dump($friends_BA);

Answer 2

You want a function that will find a specific value on a specific field in the array,
function arraySearch($key, $value, $array){
$flag = FALSE;
foreach($array as $result){
if(arraySearch($key, $value, $result)){
$flag = TRUE
}elseif(isset($result[$key] && $result[$key] == $value){
$flag = TRUE;
}
}
return $flag
}
to improve performance rather than setting $flag to true, you could return true as it will stop the execution of the function and prevent it from continuing to search the array.
Call it like so
foreach($fqlResult as $result){
if(arraySearch('concentration', 'Business Administration', $result)){
//You have found a user you are looking for, echo $result['name'] or do what you want with the result.
}
}