How to make an average of array values - php

Question

I have a database with multiple records. It is structured like this:
["data"]=>
array(5) {
[1]=>
[2]=>
array(11) {
[0]=>
string(1) "0"
[1]=>
string(8) "25000000"
[2]=>
string(3) "day"
[3]=>
string(5) "0.00%"
[4]=>
string(9) "404049904"
[5]=>
string(1) "0"
[6]=>
string(5) "0.00%"
[7]=>
string(1) "0"
[8]=>
string(1) "0"
[9]=>
string(1) "0"
[10]=>
string(3) "0.0"
}
I need to fetch the 8th record and I do this by using
public static function($data)
{
$array = [];
$path = $data->data[2];
foreach($path as $key => $item)
if($key > 1)
{
$array[] = [$item->data[8]];
}
return json_encode($array);
}
This foreach takes all the 8th values from the array but I need to display a single number which is the average of all the 8th values. How can I do this?

Answer 1

Once you've got your array containing all your data, simple sum the array and then divide by the size of the array.. something along these lines
$average = (array_sum($array) / count($array));
Of course you may want to check for count($array) being 0;

Answer 2

Because you put your value into a new array, you can not use array_sum to sum the values, so you should store it.
$sum = 0;
foreach($path as $key => $item)
if($key > 1) {
$array[] = [$item->data[8]];
$sum += $item->data[8];
}
}
$avg = ($sum / count($array); //the average
var_dump($avg);
If is it possible, just put it as a value:
$array[] = $item->data[8]; //no wrapping []
In this case, you can use $avg = array_sum($array) / count($array);

Answer 3

if (count($array)>0){
$avg = array_sum($array) / count($array);
}

Answer 4

I would personally do those calculations in the database before the data gets to your PHP script itself. See AVG().
If you can't for some reason use that I would output those values into a flat array and then just calculate the average. So something like :
function getAverage($data) {
$flatArray = array();
foreach ($data as $row) {
if (!empty($row->8)) {
$flatArray[] = $row->8;
}
}
return (array_sum($flatArray)/count($flatArray));
}
EDIT: Moved to Object traversing on the data row, sorry, missed that initially and thought it was an array in all the nests.

Answer 5

Since you have a loop within your static Method; why not do the calculation therein and return it or add it to the JSON Data if You need your Data in JSON Format? Here's what's implied by the above:
public static function getAverageSum($data) {
$array = [];
$path = $data->data[2];
$sumTotal = 0.00; //<== YOU COULD JUST SUM IT DIRECTLY WITHOUT USING AN ARRAY
foreach($path as $key => $item) {
if ($key > 1) {
$array[] = $item->data[8];
$sumTotal += floatval($item->data[8]);
}
}
// IF YOU ARE ONLY INTERESTED IN THE AVERAGE SUM YOU COULD EVEN ADD IT IT TO THE $array AS AN EXTRA KEY
// LIKE SO:
$arrLen = count($array);
$array['avgSum'] = $sumTotal/$arrLen;
// IF YOU NEED YOUR DATA IN JSON... THEN RETURN THE JSON ENCODED DATA WITH SUM AS PART OF THE DATA.
// YOU'D HAVE NO NEED FOR array_sum() SINCE YOU DID YOUR PREP-WORK ALREADY...
return json_encode($array);
// ALTERNATIVELY; IF ALL YOU NEED IS JUST THE AVERAGE SUM; YOU COULD AS WELL DIRECTLY RETURN $sumTotal/$arrLen
return ($sumTotal/$arrLen);
}