sum unknown number of post fields

[lindm]

I am trying to make a script that does the following:

 

Say I have x number of fields in a form named like the following:

FieldA1y

FieldA1x

FieldA2y

FieldA2x

FieldA3y

FieldA3x

etc etc

FieldASUMy

FieldASUMx

 

The script should calculate a sum for all fields with beginning with FieldA and ending with y as one sum and beginning with FieldA and ending with x as one sum. The field FieldASUMX or y should not be included in the sum. Not much I got so far:

 

function sum($field) {
$total = 0;

//code

return $calc[$field] = $total;	
}

The script would be called like sum("FieldASUMx"). This would sum all fields beginning with FieldA and ending with x, however not the FieldASUMx field.

[PFMaBiSmAd]

Start by using HTML arrays - http://us2.php.net/manual/en/faq.html.php#faq.html.arrays

[lindm]

Went through the array functions at http://www.w3schools.com/PHP/php_ref_array.asp but can't find a good function for me. Code to explain:

<?php

$_POST=array( 
"RRintNOcy" => "1", 
"RRintNOpy" => "2", 
"RRintVLcy" => "3", 
"RRintVLpy" => "4", 
"RRintSUMcy" => "5", 
"RRintSUMpy" => "6" 
); 
function sum() {
return array_sum($_POST[only values of keys beginning with RRint and ending with cy AND not containing SUM);
}
echo sum();
?>

Should return 4.

[waynew]

He said HTML arrays.

[lindm]

Understand. Since I need to use the id tag for all my text fields (jquery) each text field still needs to be unique. This is the code I currently use. Is it slow for larger forms/is there more efficient code?

$_POST=array( 
"RRintNOcy" => "1", 
"RRintNOpy" => "2", 
"RRintVLcy" => "3", 
"RRintVLpy" => "4", 
"RRintSUMcy" => "5", 
"RRintSUMpy" => "6" 
); 


function sum($name,$yr){
$total = 0;

foreach ($_POST as $k => $v) {
		if(substr($k,0,-4)==$name&&substr($k,-2)==$yr){
            $total += $v;
	}
}	
return $total; 

}
echo sum(RRint,cy);