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@NogDogJun 30.2011 — #One possibility would be to add a $sum parameter to the function, and have it passed by reference. Then as long as you use the same variable name on each call to that function, at any time you can then look at it and see what the current total is.
Output:
@NogDogJul 01.2011 — #Terry Pratchett is my favorite living author. ?
The "&" means that variable is beingpassed by reference . Otherwise, by default function parameters are copies* and anything done to them within the scope of the function is local only to that scope, whereas the passed-by-reference variable is sort of like a C pointer, so anything the function does to that variable affects it in the global scope, too.
Ultimately, a possible "better" solution would be to define a class that would include that function and also a class variable that would keep track of the total for you, keeping things self-contained within a single object.
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Sum of Variables
This problem started life as a javascript issue, but I think the solution is more php orientated.
I have created a function that takes its inputs passed from a loop.
[code=php]function despatch($ref, $product, $lngth, $wdth, $wt, $type){
//calculations here
}
The variables correspond to fields in MySQL recordset row. It calculates the delivery charges finishing with a variable called $fincharge. That bit works well. However, as I am calculating totals on the fly and not saving them in a table, I can not calculate the total delivery cost if there is more than one $fincharge because the function calculates a $fincharge for each item, returns the result, ‘forgets’ the result and then runs the function for the next item in the loop.
I have considered array_push, but I believe it raises a warning if the first input is not already an array.
Does anybody know how to create a sum of variables when each ‘list’ is of an unknown length and each variable effectively has the same name?
More info can be happily supplied.
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@NogDogJun 30.2011 — #One possibility would be to add a $sum parameter to the function, and have it passed by reference. Then as long as you use the same variable name on each call to that function, at any time you can then look at it and see what the current total is.[code=php]
<?php
// note the "&" in front of &$sum
function despatch($ref, $product, $lngth, $wdth, $wt, $type, &$sum){
//calculations here
$fincharge = 1; // just for testing
$sum += $fincharge;
return $fincharge;
}
for($ix=1; $ix <= 5; $ix++) {
$result = despatch(1, 2, 3, 4, 5, 6, $total);
printf("<p>#%d: This charge: %d, Sub-Total: %d</p>n", $ix, $result, $total);
}
echo "<p>Grand total: $total</p>";
[/code]Output:
<i>
</i>#1: This charge: 1, Sub-Total: 1
#2: This charge: 1, Sub-Total: 2
#3: This charge: 1, Sub-Total: 3
#4: This charge: 1, Sub-Total: 4
#5: This charge: 1, Sub-Total: 5
Grand total: 5
0
@NogDogJul 01.2011 — #Terry Pratchett is my favorite living author. ?The "&" means that variable is being
Ultimately, a possible "better" solution would be to define a class that would include that function and also a class variable that would keep track of the total for you, keeping things self-contained within a single object.
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** If you're a Pratchett fan, I figured you'd enjoy some footnotes.