question

You can get the item count by querying the storage system for items with a specific sku.

int countStorage = Storage.system.queryItems("WHERE sku == $1", 0, sku).length;

Or you use the "Table.query()" command to query the list and receive a table with counts for all available sku types. Since empty sku types will not appear in the list you can not count on a specific sku to always being found in the same row, so you would have to search for the correct row. This does have the advantage that you can get a complete table of contents with a single command, as opposed to just the count for one sku.

Table queryResult = Table.query("SELECT COUNT(sku) AS Count, sku FROM ItemList1 GROUP BY sku ORDER BY sku ASC");
int countQuery = queryResult.getValueByKey(sku, 1, 2);

You can also push the different skus to different partitions on the list to begin with, so you can retrieve their count via the "PartitionContent" statistic of the list. This method should be much faster with large item quantities than the other two, so depending on how often you query the content, I would recommend this approach. You would then specify the sku in the partition field rather than the query, when pulling items from the list.

int countPartition = getstat(List("ItemList2").as(treenode), "PartitionContent", STAT_CURRENT, sku);

GetStorageCount.fsm