How to group this PHP array by date and sum the values [closed]

Answer 1

Looks like the simplest way would to be to aggregate the counts into an array with the date as the key. You could then sort on the key and output the data however you desired.

Consider this:

$totalsByDate = [];
foreach ($array as $element) if (($date = strtotime($element->thedate)) and is_numeric($element->theadults)) {
    $totalsByDate[$date] += $element->theadults;
}
ksort($totalsByDate);
foreach ($totalsByDate as $date => $total) {
    echo "On " . date("Y-m-d", $date) . " there were " . $total " adults.\n";
}

You could also replace the ksort() with krsort() if you wanted the dates sorted in descending order.

Answer 2

You have:

• an array with $adults, where each $adult is object with thedate and theadults properties.

Now you want to make $groupedAdults, which will be array using thedate property as key. So the logic could look like this:

1. foreach ($adults as $adult):
2. $date = $adult->thedate
3. check if array_key_exists($date, $groupedAdults)
4. if no, copy current $adult to $groupedAdults[$date]
5. if yes, add $adult->theadults to the $groupedAdults[$date]->adults

Give it a try, hopefully you will be able to write it on your own now.

Answer 3

Try something like below

<?php

$array= array(
    array("thedate"=>"2016-03-05","theadults"=>10),
    array("thedate"=>"2016-03-05","theadults"=>1),
    array("thedate"=>"2016-03-06","theadults"=>1),
    array("thedate"=>"2016-03-07","theadults"=>1),
    array("thedate"=>"2016-03-05","theadults"=>1),
    array("thedate"=>"2016-03-07","theadults"=>1),
    array("thedate"=>"2016-03-06","theadults"=>1)
    );

print_r($array);
$new = array();
for($i=0;$i < count($array);$i++)
{
    $index = -1;
    for($j=0;$j<count($new);$j++)
    {
        if($array[$i]['thedate'] == $new[$j]['thedate'])
        {
            $index = $j;
            breck;
        }
    }
    if($index == -1)
    {
        array_push($new, $array[$i]);
    }
    else
    {
        $new[$index]['theadults'] += $array[$i]['theadults'];
    }
}
echo "<hr>";
print_r($new);