Question

class A
{
    public static List<String> a = new List<string>();

    public static List<String> test()
    {
        A.a.Add("20");
        A.a.Add("30");
        A.a.Add("40");
        return a.Sort();

    }
}

Throws up a compile error :

Cannot implicitly convert void to System.Collections.Generic.List.

But, If I write a method to get the List<String> value (since it is the static member variable) everything should work fine. But, I am unaware why despite my method returning a List<String> value, why does the compiler throw this error ?

Answer 1

But, I am unaware why despite of my method returning a List value, why does the compiler throw this error ?

The List<T>.Sort() method doesn’t return a List<T>. It’s a void method – it sorts the list in place. You need:

a.Sort();
return a;

Basically a method with a void return type can only be used as a standalone statement. You can’t use it as an expression to return, or as a method argument etc.