Question

I often have similar constructions:

var t = from i in Enumerable.Range(0,5)
        select num(i);

Console.WriteLine(t.Count());
foreach (var item in t)
    Console.WriteLine(item);

In this case LINQ will evaluate num() function twice for each element (one for Count() and one for output). So after such LINQ calls I have to declare new vatiable: var t2 = t.ToList();

Is there a better way to do this?

Answer 1

You can call ToList without making a separate variable:

var t = Enumerable.Range(0,5).Select(num).ToList();

EDIT: Or,

var t = Enumerable.Range(0,5).Select(x => num(x)).ToList();

Or even

var t = (from i in Enumerable.Range(0,5)
         select num).ToList();