Question

id like to know how I can execute this.

say i have an array of values
[0] 123
[1] 23242
[2] 123123
[3] 134234
[4] 0
[5] 12312
[6] 1232
[7] 0
[8] 2342
[9] 0

How can i loop through this array and everytime it hits a zero, push into a new array, the sum of the preceeding values up to the last 0

eg….
my new array would contain.
[0] sum of first array keys [0-4]
[1] sum of [5-7]
[2] sum of [8-9]

Im new to PHP and cant wrap my head around how I would do this.
Like how can I look at previous values while looking through an array

thanks if anyone can help
I appreciate it

UPDATE:
So Joe wanted me to update this so he could help me further, so here it is…

I want to loop through and array, have the iterator do the math to find the sums between the zeros, and store in a new array, the value, and a running total. And then I want to be able to merge it back into the original array….eg
How do I do the running total along with the new array.

       Loop array        New Array, with comma delimitted values or maybe a MDA
       [0]5              [0]9,9  (sum of values in loop array between the zeros)
       [1]4              [1]7,16
       [2]0              [2]4,20 
       [3]3              [3]5,25
       [4]2 
       [5]2
       [6]0
       [7]4
       [8]0
       [9]3
       [10]2
       [11]0

And finally, the most important,
How do I merge it back so it will look like the following

       [0]5             
       [1]4             
       [2]0,9,9            
       [3]3              
       [4]2 
       [5]2
       [6]0,7,16
       [7]4
       [8]0,4,20
       [9]3
       [10]2
       [11]0,5,25

Thank you if you can help me!

Answer 1

$total = 0; // running total
$totals = array(); // saved totals

foreach ($values AS $value) // loop over the values
{
    $total += $value; // add to the running total
    if ($value == 0) // if it's a zero
    {
        $totals[] = $total; // save the total...
        $total = 0; // ...and reset it
    }
}

---

For making the first array in your update, something like this:

$total = 0; // running total - this will get zeroed
$grand_total = 0; // running total - this won't be zeroed
$totals = array(); // saved totals

foreach ($values AS $value) // loop over the values
{
    $total += $value; // add to the running total
    $grand_total += $value; // add it to the grand total
    if ($value == 0) // if it's a zero
    {
        $totals[] = $total . ',' . $grand_total; // save the total and the grand_total
        $total = 0; // ...and reset the zeroable total
    }
}

---

And for your second (“ultimate” :P) example, we just bin the new array, and instead save back into the array we’re looping:

$total = 0; // running total - this will get zeroed
$grand_total = 0; // running total - this won't be zeroed

foreach ($values AS $key => $value) // loop over the values - $key here is the index of the current array element
{
    $total += $value; // add to the running total
    $grand_total += $value; // add it to the grand total
    if ($value == 0) // if it's a zero
    {
        $values[$key] = '0,' . $total . ',' . $grand_total; // build the new value for this element
        $total = 0; // ...and reset the zeroable total
    }
}

Not tested at all, but I think the logic of it should be pretty much there.