C# get object from list where object.value equals

Question

So I have a list of objects from a class. In this list I want to get the object where Table.name == "value"

Class Table{

    public string name;
    private string primarykey;
    private string[] columnNames;

    //some methods and functions
}

My question is there an efficient way to get the specified object from this list with linq for example or do I just loop through this with a basic searching algoritm.

With a basic search algoritm I mean:

foreach(Table t in tables)
{
    if(t.name == "value")
        return t;
}

So is there a more efficient way to do this with linq for example?

linq doesn't make your code magically faster. So while you could use tables.Single(t => t.name == "value"), it will not be faster. — sloth
– sloth, Commented Jan 26, 2015 at 8:20
I am aware it doesnt make it faster, but it does make it more readable with linq — kpp
– kpp, Commented Jan 26, 2015 at 8:29
If you're interested in readability more than efficiency, please make sure that next time you indicate that in your question - you talk about "efficient" twice in the question, but never mention that you actually just want simpler code. — Jon Skeet
– Jon Skeet, Commented Jan 26, 2015 at 8:32

Jon Skeet · Accepted Answer · 2015-01-26 08:20:04Z

17

You can easily do it with LINQ, but it won't be more efficient:

var match = tables.FirstOrDefault(t => t.name == value);

Now match will be null if there are no tables matching that criterion. You need to work out what you want to happen in that case.

The LINQ code is shorter, but will still have to iterate over every table in the list until it finds a match.

You might want to consider a Dictionary<string, Table> to map names to tables - but obviously that requires that there's only a single table per name. Also, unless you really have a lot of tables, you may well find that it's no quicker really. It's O(1) (assuming no hash collisions) instead of O(n), but when n is small, O(n) is really pretty fast. I strongly suggest that you check whether this is actually a bottleneck before worrying about the efficiency of it.

answered Jan 26, 2015 at 8:20

Jon Skeet

1.5m893 gold badges9.3k silver badges9.3k bronze badges

Sign up to request clarification or add additional context in comments.

7 Comments

Hossam Barakat Over a year ago

I believe it worth mention that LINQ will not make his code faster

Jon Skeet Over a year ago

@HossamBarakat: As I did, twice.

Memet Olsen Over a year ago

asked 4 mins ago, answered 3 mins ago. Skeet strikes again.

Hossam Barakat Over a year ago

Oh Great, It seems that I was viewing old version !

kpp Over a year ago

I have a dictionary(list for testing) which contains the table details. They are used to generate a dynamic query. It saves the table name in the result of this query. Now in the result from this query I need to get the column names from the specified table and that is why I need this search algorithm. I am aware it does not make it faster but it does make it more readable. Thanks for this answer.

|

Collectives™ on Stack Overflow

C# get object from list where object.value equals

1 Answer 1

7 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

7 Comments

Your Answer

Sign up or log in

Post as a guest

Related