[SOLVED] Error 'Undefined offset:...' when summing elements from 1 array to another array

[artoak]

I am summing elements from 1 array to another array using some code that is independent of array length. In the example here the answer is correct but I'm still getting these non fatal errors. I'm presuming the error is to do with setting the array key but since my arrays are of variable length, I cannot figure out how to set this 'key' attribute. Any ideas would be greatly appreciated.

 

Notice: Undefined offset: 0 in /home/www/... on line 29

 

Notice: Undefined offset: 1 in /home/www/... on line 29

36 49

 

<?php

 

$year = array(0 => 21, 1 => 28);

$ydata = array(0 => 15, 1 => 21);

 

// prints an element

function myPrint($value)

{

  print "$value ";

}

 

//add every element of 1 array with matching element of different array

 

$sum_array = array_sum_values($year, $ydata);

array_walk($sum_array, "myPrint");

 

function array_sum_values() {

    $return = array();

    $arrArgs = func_get_args();

 

    foreach($arrArgs as $arrItem) {

foreach($arrItem as $k => $v) {

            $return[$k] += $v;                                //***Line 29***

        }

    }

    return $return;

}

?>

[genericnumber1]

The simplest way would just be to set it if it's not set... so the loops become

 

<?php
    foreach($arrArgs as $arrItem) {
      foreach($arrItem as $k => $v) {
            if(!isset($return[$k])) {
                $return[$k] = 0;
            }
            $return[$k] += $v;
        }
    }
?>

 

Obviously I didn't check your logic since you said your answer was correct.

[artoak]

Thank you very much. Your solution is elegant and clearly what appears logical to me, often isn't. I continue my learning curve.