check if list contains item with matching string property

Question

im making an inventory of items, i have an items class with each item instance having a name and quantity, i want to add items to the list if the check returns with "not$$anonymous$$ng found." If i find somet$$anonymous$$ng and the quantity is 1 or more, i want to increase that items quantity instead of adding a new object.

Im using C#

 public void AddItem(string name, int price, string type, int value, string info, int quantity, bool equipped){
         for(int I = 0; I < items.Count; I++){
             if(items[I].itemName == name){
                 items[I].quantity += quantity;
             }
             else{
                 Item ni = new Item();
                 ni.itemName = name;
                 ni.price = price;
                 ni.type = type;
                 ni.value = value;
                 ni.info = info;
                 ni.quantity = quantity;
                 ni.equipped = equipped;
                 items.Add (ni);
                 
             }
         }
     }

Answer 1

Ah, I actually didn't notice that. What you're doing now is going through the items in "items", and for every item, if it is not the same as the item you're trying to add, it will add it. So if you have a list of 10 items and try to add an item that is not in the list, you will add the item 10 times.

You could do somet$$anonymous$$ng like t$$anonymous$$s:

 public void AddItem(string name, int price, string type, int value, string info, int quantity, bool equipped){
 
             bool isInList = false;
 
             for(int I = 0; I < items.Count; I++){
                 if(items[I].itemName == name){
                     items[I].quantity += quantity;
                     isInList = true;
                 }
             }
 
             // Outside for loop
             if (isInList == false){
                 Item ni = new Item();
                 ni.itemName = name;
                 ni.price = price;
                 ni.type = type;
                 ni.value = value;
                 ni.info = info;
                 ni.quantity = quantity;
                 ni.equipped = equipped;
                 items.Add (ni);
             }
         }

Noticed you're using a list, and ofc items.Count is fine

Answer 2

Answer by dmg0600 · Sep 21, 2014 at 11:59 AM

Using Linq t$$anonymous$$s is pretty easy. You would have to add using System.Linq;

 public void AddItem(string iname, int price, string type, int value, string info, int quantity, bool equipped){
 
     Item foundItem = items.FirstOrDefault(i => i.itemName == iname);
     if (foundItem != null)
     {
         Item ni = new Item();
         ni.itemName = name;
         ni.price = price;
         ni.type = type;
         ni.value = value;
         ni.info = info;
         ni.quantity = quantity;
         ni.equipped = equipped;
         items.Add(ni);
     }
     else
         foundItem.quantity++;
 }

T$$anonymous$$s way it will look for the first item in the list with that name. If there is no item with that name, it will create a new one and add it to the list, if the item is found it will increase its quantity.

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Punkjim420 · Sep 21, 2014 at 12:10 PM 0

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Oh a second method, i did not see this one. I will look at this method also.

Punkjim420 · Sep 21, 2014 at 12:20 PM 0

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ok, i read up on FirstOrDefault (here: http://msdn.microsoft.com/en-us/library/vstudio/bb340482(v=vs.100).aspx) and found that it worked too. I can't accept two answers as correct so i voted up this reply and accepted the first answer. Ive learned from both of your answers. Thank you for taking the time to teach me.

OtisMiller · Apr 22, 2017 at 03:49 PM 0

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Hi. I used this code and it worked, thanks! However it fails if there is ever no such item in my inventory (object reference error). Is there a way around this? Also is there a way of doing this multiple times without defining 3 separate 'foundItems'?

I started learning to code this year in 2017 so forgive my ignorance.

Orders.currentOrder = orders.FirstOrDefault (i => i.orderName == orderDrpdown.captionText.text);

check if list contains item with matching string property

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