====== valueSum() ======

''float **valueSum**(string //Question//)''

''float **valueSum**(string //Question//, string|array //Items//)''

''float **valueSum**(array //Variables//)''

Calculates the sum of answer codes for all items of a question (e.g. a scale), for selected items or for a list of variables.

  * //Question// -- Die Kennung einer Frage (als String)
  * //Items// -- A list (string or array) of items, e.g.
    * ''array(2,4,6)''
    * ''[2,4,6]''
    * '''1-3,5,7'''
  * //Variables// -- A list (array) of variable identifiers according to the **Variables overview**, e.g.
    * ''['AB01_01', 'AB01_02', 'BB01', 'BC01']''

    
**Note:** The function ''valueSum()'' can only read regular variables from questions and items. The dwell time ("TIME001", "TIME002", ...) cannot be read by means of ''valueSum()''. Please use the function [[:en:create:functions:casetime]] and the operator for addition (''+'') for this.

===== Examples =====

Calculate sum over all responses in scale AB01.

<code php>
$sum = valueSum('AB01');
</code>

Sum over items 2, 4, 6, and 8 of the AB01 scale.
<code php>
$sum = valueSum('AB01', [2,4,6,8]);
</code>

Sum over the first 4 items of the AB01 scale.
<code php>
$sum = valueSum('AB01', '1-4');
</code>

Sum over the responses in variables AB01_01, AB01_03, and BB01_02 (as [[:en:create:array|array]] in square brackets).

<code php>
$sum = valueSum(['AB01_01','AB01_03','BB01_02']);
</code>

The same command again a little more clearly
<code php>
$sum = valueSum([
           'AB01_01',
           'AB01_03',
           'BB01_02'
       ]);
</code>