PHP Get duplicate values in array and average second value - php

Question

I have an array that looks like this:
$ratingsInPosts = array
(
array("1",3),
array("2",5),
array("2",2),
array("5",2),
array("90",1),
array("5",6),
array("2",2),
);
I Want to find duplicate values in the first column and avarage its values from the second column.
So that this("1",3),("2",5),("2",2),("5",2),("90",1),("5",6),("2",2)
ends up like this ("1",3),("2",3),("5",4),("90",1)

Answer 1

Try this tested solution
I got the required Output
$ratingsInPosts = array
(
array("1",3),
array("2",5),
array("2",2),
array("5",2),
array("90",1),
array("5",6),
array("2",2),
);
$arr1 = array_column($ratingsInPosts, 0);
$p = array_count_values($arr1);
foreach($p as $key => $value)
{
$sum = 0;
for($i=0; $i < $value; $i++)
{
$pos = array_search($key, $arr1);
$sum += $ratingsInPosts[$pos][1];
unset($arr1[$pos]);
unset($ratingsInPosts[$pos]);
}
$re[] = array('"'.$key.'"',$sum/$value);
}
print_r($re);

Answer 2

I hope it helps you:
$groups = array();
// in this loop we group values by first column
foreach ($ratingsInPosts as $row) {
$key = $row[0];
if (!isset($groups[$key]) {
$groups[$key] = array();
}
$groups[$key][] = $row[1];
}
$result = array();
foreach ($groups as $key => $value) {
$avg = array_sum($value) / count($value);
$row = array($key, $avg);
$result[] = $row;
}

Answer 3

<?php
header('Content-Type: text/plain');
$ratingsInPosts = array(array("1",3),array("2",5),array("2",2),array("5",2),array("90",1),array("5",6),array("2",2));
$result = array();
$output = array();
foreach($ratingsInPosts as $array){
$result[$array[0]][] = $array[1];
}
foreach($result as $key=>$array){
$output[] = array($key,round(array_sum($array)/count($array)));
}
var_export($output);
?>