Question

I am working on ASP.net MVC 3.0 Razor View Engine Application.
I have a Advance Search form to get the list of Customers found
Which will have fields like

FirstName TextBox

LastName TextBox

DOB TextBox

Address TextBox

Gender DropDown

Zipcode TextBox

Ignore Address checkBox

Finally the Submit Button.
I have a list of Customers in a List object.
No field is Mandatory in the Search Form.
When User hits search based on the Values he provided in the Form,
my Logic should return the matching results from the List Object that is holding all Customer details.

So I would like to pick an idea from you.
to write a best logic that will find the Customer based on user provided info.

I started with something like this

if (fname != "" && lname == "")
        {
            return _CustomerList.FindAll(p => p.FirstName == fname);
        }
        else if (fname == "" && lname != "")
        {
            return _CustomerList.FindAll(p => p.LastName == lname);
        }

        else if (fname != "" && lname != "")
        {
            return _CustomerList.FindAll(p => p.FirstName == fname && p.LastName == lname);
        }
return _CustomerList;

I don’t think this is an efficient way.

Any advises would be a great help.
thank you for reading. 🙂

Answer 1

Use Linq instead and an IEnumerable<Customer> – you can compose your query with additional Where() clauses as needed and at the end return the matching items as list using ToList().

var matchingCustomers = _CustomerList;

if (!string.IsNullOrEmpty(lname))
{
    matchingCustomers = matchingCustomers.Where(x => x.LastName == lname);
}

if (!string.IsNullOrEmpty(fname))
{
    matchingCustomers = matchingCustomers.Where(x => x.FirstName == fname);
}

//...

return matchingCustomers.ToList();