Average from inner array - php

Question

my task is to calculate average value from an array.
$arrayToTest = [[[1], 1], [[1,3,5,7], 4], [[2,5,4,1,2,3], 2.8],
[[-1,-1,-1,-1,-1], -1], [[4,23,84,12,76,34,-7,-23], 25.375]];
From inner array, so for example [1,3,5,7] and expected value is 4.
I have to use a function, I tried this:
function arrayAverage ($arrayToTest)
{
foreach($arrayToTest as $case)
foreach ($case as $item)
{
$arraySum = array_sum($item);
$arrayCount = array_count_values($item);
$average = $arraySum / $arrayCount;
return $average;
}
}
but it does not work. I feel I'm doing something wrong with calling the inner array.

Answer 1

Comment:
I assume that you wish to calculate the average values of the innermost arrays.
The solution below returns the average of each array - not the average of all arrays. But - of course you easily could calculate the average of all arrays.
Therefore the function arrayAverage(…) returns an array of average values instead of the average value of (only) the last array.
I declared the input array (arrayToTest) explicitely, for the reason that one can better see the array structure (array of arrays and scalars) like this.
Code:
<?php
$arrayToTest = array (
array(
array(1),
1
),
array(
array(1,3,5,7),
4
),
array(
array(2,5,4,1,2,3),
2.8
),
array(
array(-1,-1,-1,-1,-1),
-1
),
array(
array(4,23,84,12,76,34,-7,-23),
25.375
)
);
echo '<pre>'; print_r($arrayToTest); echo '</pre>';
$average = arrayAvarage ($arrayToTest);
echo '<pre>'; print_r($average); echo '</pre>';
function arrayAvarage ($arrayToTest) {
$result = array();
foreach($arrayToTest as $case) {
foreach ($case as $items) {
if (!is_array($items)) continue;
$result[] = array_sum($items) / count($items);
}
}
return $result;
}
?>
Result:
Array
(
[0] => 1
[1] => 4
[2] => 2.8333333333333
[3] => -1
[4] => 25.375
)

Answer 2

if your array contains internal arrays in the index 0, you can do this by:
function arrayAvarage ($arrayToTest)
{
$out_put_arr = array();
foreach($arrayToTest as $case)
{
$arraySum = array_sum($case[0]);
$arrayCount = array_count_values($case[0]);
$avarage = $arraySum / $arrayCount;
$out_put_arr[]= $avarage;
}
return $out_put_arr;
}
so the loop for the main array, each item in the main array will give you array, and int $case[0] = [1,3,5,7] and $case[1] = 4, also you shouldn't return in for loop because this will return the first average only. so you can declare new array to fill with all averages.

Answer 3

function average($array){
return array_sum($array) / count($array);
}
foreach($arrayToTest as $array){
echo "Average: " . average($array[0]);
}

Answer 4

You should look at the first element of the $case array, which is the actual place where the array with values is situated. Note that you can also use the array_sum function.
Also, you should not return just like that, because that will interrupt the function from doing anything more. So, only return when you really want to do that.
As you already have expected values, I see no reason why your function should return those averages again. Instead it could verify the correctness of these expected values, and return the index of the array when that comparison fails.
function arrayAverage ($arrayToTest)
{
foreach($arrayToTest as $index => $case) {
$average = array_sum($case[0]) / count($case[0]);
if ($average !== $case[1]) {
return $index; // not expected value
}
}
return false; // all averages are equal to expected value
}
So, the above function will return FALSE when all averages are as expected. Otherwise it will return the index of the first mismatch.