C# use Linq method instead of for loop

Question

I have a string array and a for loop to add items to list.

Here is my code:

//customers table : 
// Firstname, Lastname, Age, BrowserName, Date

string[] browsers = {"chrome", "Firefox", "Edge"}
var users = db.customers.ToList();

list<string> names = new List<string>();

for(var i = 0; i < browsers.lenght; i++) {
     names.Add(users.where(x => x.BrowserName == browsers[i]).FirstName);
}

Is there any way to use Linq method or something else instead of for ?

It really doesn't help that you've posted pseudo-code instead of *real* code. As that's not your real code, we can't be sure that there isn't something important in your real code that you've left out. Please provide a [mcve]. But unless you care about the order, you can probably just use `var names = db.Customers.Where(u => browsers.Contains(u.BrowserName)).Select(u => u.FirstName).ToList();`. (You shouldn't call `db.Customers.ToList()` in general, as that will pull *all* the customers from the database...) — Jon Skeet, May 13 '17 at 07:20
I'm not sure it is a total duplicate as flagged by @CodeCAsterYou can replace your `for` loop with this: `names.AddRange(users.where(x => browsers.Contains(x.BrowserName)).Select(x => x.FirstName));` — Frank Fajardo, May 13 '17 at 07:36
I'm not sure the SO item marked as duplicate of this is correct, or is answering this question. — Frank Fajardo, May 13 '17 at 07:44
@FrankFajardo: The accepted answer definitely doesn't provide the most idiomatic way of using LINQ to create a list though, which is what the OP is trying to do. I don't think it's actually a *useful* duplicate in this case, so I've reopened. But the OP should definitely edit the question to be better... — Jon Skeet, May 13 '17 at 08:03

score 3 · Answer 1 · edited May 13 '17 at 11:26

3

Instead of

for(var i = 0; i < browsers.lenght; i++) {
    names.Add(users.where(x => x.BrowserName == browsers[i]).FirstName);
}

Use this

names = users.Where(x => browsers.Contains(x.BrowserName)).Select(y => y.FirstName).ToList();

edited May 13 '17 at 11:26

OmG

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answered May 13 '17 at 08:52

Deepak Tiwari

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7

OmG · Answer 2 · 2017-05-13T08:35:49.663

1

You can do it by foreach like the following:

browsers.ToList().Foreach(x => users.where(y => y.BrowserName == x).ToList().Foreach(z => names.Add(z.FirstName)))

edited May 13 '17 at 08:35

answered May 13 '17 at 08:30

OmG

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C# use Linq method instead of for loop

2 Answers2