Multidimensional Array - Search for value and get the sub-array

Question

Given an array like

$clusters = array(
"clustera" => array(
 '101',
 '102',
 '103',
 '104'
),
"clusterb" => array(
 '201',
 '202',
 '203',
 '204'
),
"clusterc" => array(
 '301',
 '302',
 '303',
 '304'
)
);

How can I search for a server (e.g. 202) and get back its cluster? i.e. search for 202 and the response is "clusterb" I tried using array_search but it seems that is only for monodimensional arrays right? (i.e. complains that second argument is the wrong datatype if I give it $clusters)

Answer 1

$search=202;
$cluster=false;
foreach ($clusters as $n=>$c)
 if (in_array($search, $c)) {
 $cluster=$n;
 break;
 }
echo $cluster;

• Seer: something funky going on. Seemed you missed a brace or something anfd I tried to clean up but can't get it working. $search=$server; $cluster=false; foreach ($clusters as $n=>$c) { if (in_array($search,$c)) { $cluster=$n; break; } } print("method 2 got: "$cluster)
• Eugen Rieck: Just checked my code here, works as expected. Your code is wrong in the last line, print("method 2 got: "$cluster);should be print("method 2 got: $cluster");
• Seer: Absolutely right ... but even that was not the issue .... I was testing with 202 when in fact I hid the REAL server name from the example to protect the innocent :) Works great!

Answer 2

$arrIt = new RecursiveArrayIterator($cluster);
$server = 202;
foreach ($arrIt as $sub){
 if (in_array($server,$sub)){
 $clusterSubArr = $sub;
 break;
 }
 }
$clusterX = array_search($clusterSubArr, $cluster);

• mickmackusa: This answer is missing its educational explanation.
• Jose Manuel Abarca Rodríguez: Dear Aleksander Maj : would you add an explanation to your answer, please, it's not so easy to understand.

Answer 3

function array_multi_search($needle,$haystack){
foreach($haystack as $key=>$data){
if(in_array($needle,$data))
return $key;
}
}
$key=array_multi_search(202,$clusters);
echo $key;
$array=$clusters[$key];

Try using this function. It returns the key of the $needle(202) in the immediate child arrays of $haystack(cluster). Not tested, so let me know if this works

• Seer: This one not quite working either ... comes up empty. The only change I have made is throwing braces around the contents of the function. function array_multi_search($needle,$haystack) { foreach($haystack as $key=>$data) { if(in_array($needle,$data)) return $key; } }

Answer 4

function getCluster($val) {
 foreach($clusters as $cluster_name => $cluster) {
 if(in_array($val, $cluster)) return $cluster_name;
 }
 return false;
}

• Seer: hmm I get "Invalid argument supplied for foreach()" which is shame as it looks like it will be exactly what I need :)
• Jonny White: $clusters would need to be defined as your array of clusters as in the question