How to find the mode of an array in PHP

Question

I have an array that has been sorted from low to high which has over 260k values in. I have found out the mean(average) and median of the array just need to find out the mod

Answer 1

Simple!

$arr = array(4,6,7,1,4,7,4,7,1);
$freq = array();
for($i=0; $i<count($arr); $i++)
{
   if(isset($freq[$arr[$i]])==false)
   {
       $freq[$arr[$i]] = 1;
   }
   else
   {
       $freq[$arr[$i]]++;
   }
}
$maxs = array_keys($freq, max($freq));

for($i=0; $i<count($maxs); $i++)
{
   echo $maxs[$i] . ' ' . $freq[$maxs[$i]];
   echo '<br />';
}

Answer 2

Mathematical only solution:

    //sample data
$dataArr = ["1", "3", "5", "1", "3", "7", "1", "8", "1"];

//a multidimensional array to hold the keys (extracted fro above) and their values (number of occurrences)
$multiDArr = [];
for ($i = 0; $i < count($dataArr); $i++) {
    $key = $dataArr[$i];

    if (isset($multiDArr[$key])) {
        //key already exists; increment count of its value
        $multiDArr[$key] = $multiDArr[$key] + 1;
    } else {
        //key does nto exist; add it and an inital value of 1
        $multiDArr[$key] = 1;
    }
}

$highestOccuring = 0;
$highestOccuringKey = null;
foreach ($multiDArr as $key => $value) {

    if ($value > $highestOccuring) {
        $highestOccuring = $value;
        $highestOccuringKey = $key;
    }

}

echo "MODE / highest occuring key: " . $highestOccuringKey;

Answer 3

The mode of a numerical set is the number that occurs the most often. You can do this with PHP using code similar to the following:

$values = array_count_values($valueArray); 
$mode = array_search(max($values), $values);