LINQ to find array indexes of a value

Question

Assuming I have the following string array:

string[] str = new string[] {\"max\", \"min\", \"avg\", \"max\", \"avg\", \"min\"}

Is it possbile t

Answer 1

.Select has a seldom-used overload that produces an index. You can use it like this:

str.Select((s, i) => new {i, s})
    .Where(t => t.s == "avg")
    .Select(t => t.i)
    .ToList()

The result will be a list containing 2 and 4.

Documentation here