Question

I have a double array as follows:

$values[$ids][$dates]

So for each $id I have an array of $dates (which are actual dates in this format – date(“Y-m-d”, $i)).

What I want to do is for each date loop through the corresponding ids and sum them up. So for example, if the first date is “2012-01-01” and the ids are 1,2 and 3. I want

$values[1]["2012-01-01"]+$values[2]["2012-01-01"]+$values[3]["2012-01-01"]

And then I want

 $values[1]["2012-01-02"]+$values[2]["2012-01-02"]+$values[3]["2012-01-02"]

preferrably put into an array, which should be trivial. It’s the looping part which is confusing me.

Any ideas? Thanks.

Answer 1

foreach($values as $id => $dates) {
    foreach($dates as $date => $value) {
        $result[$date] += $value;
    }
}