[Resolved] Array summing? URGENT for project

stratguitar

I cannot figure out how to manipulate the following math dilemma.

2 arrays called $u and $c form from $_POST

Each has an identical keys, numbered 1 through 10.

The first array, $u has some empty values
The other, $c, does not

I want to sum ONLY the values in array $c that match with non-blank values in $u.

EXAMPLE
In other words, say there are 10 keys in each array, 1 through 10.

On POST:
$u has values at key 5 and 9, the rest are null
$c has values at all keys 1-10

I want to sum ONLY the $c values at 5 and 9

array_sum() works FINE for array $u, because it ignores the blanks, but it obviously will not work with $c right now and return only the integers I want.

Is this at all possible? I've tried pushing, merging and mapping the arrays, none of this seems to leave me with what I need to do my summing correctly

Thanks,
Stratguitar

Mordecai

I'm a little confused. Are you trying to add the arrays together, the information in the arrays, or add the keys?

Examples of what I mean:
Add arrays together:
$u = array(0,0,1,2,3)
$c = array(1,2,3,4,5)
$result = array(1,2,3,4,5,1,2,3)

Add information in the arrays:
$u = array(0,0,1,2,3)
$c = array(1,2,3,4,5)
$resultu = 6
$resultc = 15

Add keys:
$u = array(0,0,1,2,3)
$c = array(1,2,3,4,5)
$result = array(3,4,5)

Or, did I miss everything entirely?

stratguitar

Thanks for the first reply -

No, let me try to explain more clearly, because what I needed to originally do was rather unusual in the first place.

In my POST page, I ended up with this: (disregard the values entered, they're only examples. It changes with each post)

array $u has keys and values as follows, for example: (it will change with each new post)

Key Value
1 Blank
2 Blank
3 5
4 Blank
5 Blank
6 Blank
7 Blank
8 15
9 25
10 Blank

Okay, fine. If I do array_sum($u), obviously the total of the values is going to be 45.
So, we're dealing the values from Keys 3, 8 and 9 here.

So far so good.

However, here's the other array, $c
Key Value
1 10
2 15
3 10
4 5
5 15
6 32
7 35
8 33
9 10
10 15

I want to only pull out the values that are attached to keys 3, 8 and 9, and sum them.

I need these values because of a bunch of math I have to do using the sums of these rows.

IT GETS WORSE! But for now, this is what I need to be able to do.

Thanks again!

Strat

Mordecai

Assuming the length on both are always the same:
for ($i=0;$i<=count($u);$i++) {
if ($u[$i] = "") {
$c[$i] = "";
}
}

This simply erases every blank one from $u, and puts it into $c.

If you want to also keep the original values, just create another array.

stratguitar

I still don't think this is quite what I need. I know how to eliminate blanks from the $u array.

I do NOT know how to loop through an array and sum only the values I want.

What I NEED is the values from the $c array which ONLY match KEYS with the $u array NON-BLANK values.

In English, here's the code :😁:

Find the keys in $U where $u values is NOT blank
(say those keys are 3, 8 and 9)
then, go find the VALUES in $c that have the same KEY ID as the ones above i.e.
Select those from $c, and total those 3 values from Keys 3, 8 and 9 THERE.

In otherwords, in my message above where I spelled out the keys and values, I'd get a total of 45 as sum of $u... and from $c, I'd have ONLY 10 plus 33 plus 10, from keys 3, 8 and 9, for a total of 53.

Hope this is clearer... I know how to display them, I just don't know how to sum them.

But thanks for your help........ it's very appreciated

Strat

stratguitar

OOPS! I was wrong! I didn't read closely enough!

This MAY just work for what I need!!!! :😁:

Veeeeeeeeeeeeeeeeery clever!

Strat

Mordecai

It should work for that. Just array_sum() the new array. 🙂

diego25

Just one little detail:
if ($u[$i] = "") {
should be
if ($u[$i] == "") {

Personally, I'd do it this way:

$sum = 0;
for ($i=0;$i<=count($u);$i++) {
if ($u[$i] == "") {
$sum += $c[$i];
}
}

This way you don't destroy the array $c, which you might need later on...

Diego

Mordecai

Thanks for pointing out my mistake. Must have missed the key the second time. (Or was it the first...? 🙂)

And your way probably is better, seeing as he said there were more calculations later. I suggested creating another array, but I suppose a variable of the summed value works just as well.

stratguitar

Thanks, both of you.......... BTW, I'm using version 4.3.0
This is still not working.

However, here's what's happening, and I'm not sure why.

for ($i=0;$i<=count($u);$i++) {

THE $i<=count ($u)

takes you one row beyond the end of the array with a warning 'Unidentified offset: 94 (which is 1 more row than I have)

So I changed this to less than, rather than less or equal

$i<count($u)

AND
$sum += $c[$i];

This sums ALL but the last entry in the $c array, but none of the fields have been blanked. The total of ALL 93 rows in $c is 1200 and that's what's being returned instead of what it should hav been (10 or so.) These numbers are doubles/floats, by the way.

So, the fields we were attempting to blank out were not blanked using either method.

I also tried the original one with the == instead. That doesn't seem to do it, either - resulting in same add issue.

Is there something I'm not doing (resetting, or somesuch?) that might affect the response? Doesn't seem so, but thought I should ask.

Thanks. I'm extraordinarily grateful, in any event.
Strat

diego25

Yeah, you're right about the <= being <.

Also, instead of ==, use !=. That should give you what you want...

Diego

stratguitar

Woo - HOO!

Worked, thanks!

This is a go-live in 2 days, you folks saved my life.

By the way, this HE is a SHE. NO way you could know. PHP Rocks as much as my guitar! (And yes, I play a Strat .😃)

Ready for the next one? (let me try my theory based on the riches you've both just handed me... first.)

If I multiply a value (again, we've got matching keys) in $u by a value in $c, and display those results by row in a loop, they're appearing fine. So is that calc by row.

Can I assume that the neat, great little calc

$sum += $whatever

will work similarly inside a a similar 'for' loop?

value $b * value $c is set to variable $d and displayed in each row of the loop

so, will

$sum += $d[$i]
do the trick?
I'm betting it will. Stay tuned.

You really have no idea how this helps.........

Strat