Invalid cast from List to IEnumerable back to List, why?

Question

So basically i have this method.

public List FilterCustomersByStatus(List source, string status)
{
    return (List

        

Answer 1

The Where extension filters and returns IEnumerable hence you need to call .ToList() to convert it back

public List FilterCustomersByStatus(List source, string status)
{
    return source.Where(c => c.Status == status).ToList();//This will return a list of type customer
}