CODEWITHSUNDEEP
c#linqlinq-to-objects
DotnetDude
DotnetDude

Reputation: 11807

How do I do IN syntax with Linq

I need to do this using linq chaining syntax. I have:

string[] arr = new string[] {"Chicago", "NewYork"};

var a = Members.Where(x => x.City == <here I want to get all members in chicago or newyork)

Upvotes: 8

Views: 5629

Answers (3)

Gabriel McAdams
Gabriel McAdams

Reputation: 58251

I know this is old, but I thought this would help new readers of this post.

Similar to code4life, I use an extension method. The difference, though, is that I use generics so this will work with multiple types.

You can read my blog post to see more information about how to do this, but the main idea is this:

By adding this extension method to your code:

public static bool IsIn<T>(this T source, params T[] values)
{
    return values.Contains(source);
}

you can perform your search like this:

var a = Members.Where(x => x.City.IsIn("Chicago", "NewYork");

It works on any type (as long as you create a good equals method). Any value type for sure.

Upvotes: 5

code4life
code4life

Reputation: 15794

Static extensions work well with your LINQ needs:

// add this class to your project...
public static class StringExtensions
{
    public static bool IsIn(this string target, params string[] testValues)
    {
        return testValues.Contains(target);
    }
}

And now your original code can be changed like this:

// quick and dirty code:
var a = Members.Where(x => x.City.IsIn("Chicago", "NewYork");

// less quick and dirty code:
string[] arr = new string[] {"Chicago", "NewYork"};    
var a = Members.Where(x => x.City.IsIn(arr);

Upvotes: 0

jjnguy
jjnguy

Reputation: 138864

You can use a simple Contains.

var a = Members.Where(x => arr.Contains(x.City));

Upvotes: 9

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