Hi,

I assume that you're trying to calculate the sum of all count for a particular parent id.

If that is the case, you can add a new Map<Id, Integer> to your code as below.

Map<Id,List<List<String>>> servMap = new Map<Id,List<List<String>>>(); //Updated
Map<Id, Integer> servCountMap = new Map<Id, Integer>();
for(Service__c serObj: serviceList){
Id parentAccId = serObj.Customer__r.Grand_Parent_Account__c;
String AccountId = serObj.Customer__r.id;
String count = serObj.Customer__r.CountOfPickupDays; //Added
List<String> childDetailsList = new List<String>{AccountId, count}; //Added
if(serObj.Status__c == 'Active'){
if(servMap.get(parentAccId)==null)
{
servMap.put(parentAccId,new list<List<String>>{childDetailsList}); //updated
}
else
{
servMap.get(parentAccId).add(childDetailsList); //updated
count = String.valueOf(Integer.valueOf(count) + servCountMap.get(parentAccountId));
}
servCountMap.put(parentAccId, Integer.valueOf(count));
}

Whenever you want to get the total count for a particular parentId, you can use servCountMap.get(parentId).

Thanks,

Anoop

Oops, forgot that your count is decimal. Please note that I'd used Integer in the above code. If you're using this code, make sure proper type casting is done.

Thanks,

Anoop

Just an afterthought, with all the type casting and complicated collections, doesn't the code look a bit unclean?

For the two requirements you stated above, I think the following code will be a much more cleaner version. :)

Map<Id, List<Id>> servCustomerMap = new Map<Id, Id>();
Map<Id, Decimal> servCountMap = new Map<Id, Integer>();
for(Service__c serObj: serviceList){
    Id parentAccId = serObj.Customer__r.Grand_Parent_Account__c;
    Id AccountId = serObj.Customer__r.id;
    Decimal count = serObj.Customer__r.CountOfPickupDays;
    if(serObj.Status__c == 'Active'){
        if(servCustomerMap.get(parentAccId)==null)
            servCustomerMap.put(parentAccId,new List<String>{AccountId}); 
        else
            servCustomerMap.get(parentAccId).add(AccountId); 
        servCountMap.put(AccountId, count);
    }
}

//Now assuming that you've the parent record for calculating the count in the variable parentId. 
Decimal totalCount = 0;
for (Id accountId : servCustomerMap.get(parentId)){
    totalCount = totalCount + servCountMap.get(accountId);
}

Here, note that there will be no calculations involved even if you've multiple Service records with the same Customer record as parent. Another assumption I'd made. :D

Please feel free to share your thoughts on this.

Thanks,

Anoop