Find maximum value in PHP array - php

Question

Below is my array:
Array
(
[3] => Array
(
[2] => 3
[4] => 1
[5] => 2
[6] => 2
)
[5] => Array
(
[2] => 1
[3] => 2
[4] => 3
[6] => 3
)
In this array I want to find the maximum number and if the array contains the same maximum values then we choose one maximum value randomly.
Expected output like below:
Array
(
[3] => Array
(
[2] => 3
)
[5] => Array
(
[4] => 3
)
[6] => Array
(
[2] => 3
)
)
This is what I've tried:
$found = Array( [3] => Array ( [2] => 3 [4] => 1 [5] => 2 [6] => 2 ) [5] => Array ( [2] => 1 [3] => 2 [4] => 3 [6] => 3 ) [6] => Array ( [2] => 3 [3] => 2 [4] => 2 [5] => 3 ))
$fmaxnum = array();
foreach($found as $fk => $fv){
$fmaxnum[$fk] = max($fv);
}
echo "<pre>";print_r($fmaxnum);echo "</pre>"

Answer 1

You will get max value with max() but for index you have to use array_keys()
You can try this:
$found = Array ( '3' => Array ( '2' => 3 ,'4' => 1, '5' => 2, '6' => 2 ),
'5' => Array ( '2' => 1 ,'3' => 2, '4' => 3, '6' => 3 ),
'6' => Array ( '2' => 3 ,'3' => 2, '4' => 2, '5' => 3 )
);
$fmaxnum = array();
foreach($found as $fk => $fv){
$max_key = array_keys($fv, max($fv));
$fmaxnum[$fk] = array(
($max_key[0]) => max($fv) /* This will give small index value */
/* (count($max_key)-1) => => max($fv) // this will give highest index value */
);
}
echo "<pre>";
print_r($fmaxnum);
echo "</pre>";

Answer 2

Simple solution with array_map and array_keys functions:
// supposing $arr is your initial array
$arrMax = array_map(function($v){
$maximum = max($v);
return [array_keys($v, $maximum)[0] => $maximum];
}, $arr);
print_r($arrMax);
The output:
Array
(
[3] => Array
(
[2] => 3
)
[5] => Array
(
[4] => 3
)
[6] => Array
(
[2] => 3
)
)

Answer 3

if you just want to know the highest value as I understood
In this array I want to find the maximum number and if the array
contains the same maximum values then we choose one maximum value
randomly.
you could just do this
$array = [['3','1','2','2'],['1','2','3','3'],['2','1','1','3']];
$result = [];
foreach(new RecursiveIteratorIterator(new RecursiveArrayIterator($array)) as $value) {
$result[] = $value;
}
echo max($result);
this will foreach all the array and push the values on $result, then you just have one level array and easily use max function