Find an item in a generic list by specifying multiple conditions

Question

Most often we find generic list with code like:

CartItem Item = Items.Find(c => c.ProductID == ProductID);
Item.Quantity = Quantity;
Item.Price = Price;

So the above code finds and updates with other data, but if I want to find by multiple conditions, then how do I write the code?

I want to write code like:

CartItem Item = Items.Find(c => c.ProductID == ProductID and c.ProductName == "ABS001");

Please guide me for multiple conditions when we find generic list.

If you need you can also use || (depends on condition) – goGud Feb 27 '14 at 07:19 — goGud, Feb 27 '14 at 07:19

score 68 · Accepted Answer · edited Sep 13 '12 at 13:01

68

Try this:

CartItem Item = Items.Find(c => (c.ProductID == ProductID) && (c.ProductName == "ABS001"));

edited Sep 13 '12 at 13:01

Spontifixus

answered Sep 13 '12 at 12:56

Anton Sizikov

5

C# isn't a C++. There's no need in extra brackets. – Dennis Sep 13 '12 at 13:05
20

Yep, thnx, I know. But I use them to improve readability. It's just a code style wich become a habit. – Anton Sizikov Sep 13 '12 at 13:26
How about if you have a an `IN CLAUSE` for the second operation? – Mark Jan 07 '14 at 07:21
Something like that: (http://stackoverflow.com/questions/959752/where-in-clause-in-linq )? – Anton Sizikov Jan 07 '14 at 14:00

score 11 · Answer 2 · answered Sep 13 '12 at 12:56

11

Try this:

Items.Find(c => c.ProductID == ProductID && c.ProductName == "ABS001");

The body of lambda expression is just a method. You can use in it all language constructs, as in regular method.

answered Sep 13 '12 at 12:56

Dennis

score 5 · Answer 3 · edited Apr 07 '15 at 08:13

5

Personally, I prefer

Items.Find(item => item.ProductId == ProductID && item.ProductName.Equals("ABS001"));

edited Apr 07 '15 at 08:13

Anton Sizikov

answered Apr 24 '13 at 15:24

Mr Z

1

I tend to reverse the Equals to prevent a problem where item.ProductName is null. I would write `Items.Find(item => item.ProductId == ProductID && "ABS001".Equals(item.ProductName));` because you know "ABS001" is not null before run time. – Jay May 23 '18 at 11:03

score 3 · Answer 4 · answered Sep 13 '12 at 12:59

3

Use && instead of and

var result = Items.Find(item => item.ProductId == ProductID && item.ProductName == "ABS001");

answered Sep 13 '12 at 12:59

Zen

score 0 · Answer 5 · answered May 23 '18 at 10:54

0

It annoys me when someone named a variable with the first char in uppercase, so (productID instead of ProductID):

CartItem Item = Items.Find(c => (c.ProductID == productID) && (c.ProductName == "ABS001"));

:)

answered May 23 '18 at 10:54

tedi

5 Answers5