var = shopsByItem.computeIfAbsent, Assigns shopsByItem(?)

[shadow plume]

I'm lost.

[olive crater]

<@&987246399047479336> please have a look, thanks.

[olive crater]

While you are waiting for getting help, here are some tips to improve your experience:

Code is much easier to read if posted with syntax highlighting and proper formatting.

If nobody is calling back, that usually means that your question was not well asked and hence nobody feels confident enough answering. Try to use your time to elaborate, provide details, context, more code, examples and maybe some screenshots. With enough info, someone knows the answer for sure.

Don't forget to close your thread using the command </help-thread close:1027500463647621170> when your question has been answered, thanks.

[shadow plume]

    public void addShop(PlayerShopContainer shop) {
        PlayerShopContainer selectedShop = shopsByName.get(shop.getPlayer().getUsername());
        if (selectedShop == null) {
            shopsByName.put(shop.getPlayer().getUsername(), shop);
        }

        for (Item item : shop.getItems()) {
            String name = item.getDefinition().getName();
            List<PlayerShopContainer> shops = shopsByItem.computeIfAbsent(name, k -> new ArrayList<>());
            if (!shops.contains(shop)) {
                shops.add(shop);
            }
        }
    }

[olive crater]

Detected code, here are some useful tools:

Formatted code

public void addShop(PlayerShopContainer shop) {
  PlayerShopContainer selectedShop = shopsByName.get(shop.getPlayer().getUsername());
  if (selectedShop == null ) {
    shopsByName.put(shop.getPlayer().getUsername(), shop);
  }
  for (Item item : shop.getItems()) {
    String name = item.getDefinition().getName();
    List<PlayerShopContainer> shops = shopsByItem.computeIfAbsent(name, k -> new ArrayList<>());
    if (!shops.contains(shop)) {
      shops.add(shop);
    }
  }
}

[shadow plume]

in this function

method*

i'm assigning a local variable named shops

however, it is really assigning to a instance member:
private static final TreeMap<String, List<PlayerShopContainer>> shopsByItem = new TreeMap<>();

why, and how

specifically this part:

    String name = item.getDefinition().getName();
    List<PlayerShopContainer> shops = shopsByItem.computeIfAbsent(name, k -> new ArrayList<>());
    if (!shops.contains(shop)) {
      shops.add(shop);
    }
  }```
How is it even possible that its doing shops.add(shop)? is this because shops in this scenario is a pointer to the List assigned to the key?

[olive crater]

Detected code, here are some useful tools:

Formatted code

for (Item item : shop.getItems()) {
  String name = item.getDefinition().getName();
  List<PlayerShopContainer> shops = shopsByItem.computeIfAbsent(name, k -> new ArrayList<>());
  if (!shops.contains(shop)) {
    shops.add(shop);
  }
}

[winged storm]

Yes, the shops variable is a pointer to a list that is inside the shopsByItem map.
In java all* non-primitive variables are actually pointers to objects.

* Note: Does not apply for value-based classes when they are added to java.

[shadow plume]

aha! appreciate your reply

thanks alot

[winged storm]

If your question has been answered, use /help-thread close to close this thread.

[shadow plume]

ow excuse me my connection was lost

i asked

if you would possible be able to elaborate on what you meant by value-based classes?

and how those differ from objects?

[winged storm]

Sorry, i meant value objects. I only know a littebit about them myself and there are currently only a preview feature, so you probably don't have to know this.
If you are generally interested in learning about them, here is the jep: https://openjdk.org/jeps/8277163

[shadow plume]

thanks alot! appreciated