从另一个列表创建一个列表，并按某些索引过滤

Question

I have a List<decimal> and I want to create a new List<decimal> from a subset of the first List.

Code example:

List<decimal> set1 = new List<decimal>() { 10, 20, 30, 40, 50 };

How do I create a new List that is from index=2 to index=4 (30, 40, 50)?

Answer 1

var set2 = set1.Skip(2).Take(3).ToList();

Answer 2

var list = set1.Select((r, i) => new { Index = i, Value = r })
               .Where(t => t.Index >= 2 && t.Index <= 4)
               .Select(r => r.Value);

If you want to have a List you can append ToList to the query.

For output

foreach (var item in list)
{
    Console.WriteLine(item);
}

output:

30
40
50

Answer 3

Using GetRange

var newlist = set1.GetRange(2,3);

You are passing starting index (2) and number of items you will get (3)