asp.net mvc - MVC 3 accept null foreach in the viewModel -

i have page users can enter state information , list of other users come within state. using foreach loop.

some of states have 0 users, leads me error: object reference not set instance of object. how can past error? particular model i'm using called profiles.

the model:

public class homepage {     public list<profile> profile { get; set; }     public pagedlist.ipagedlist<article> article { get; set; } } 

the controller:

public actionresult index() {     httpcookie mypreference = request.cookies["cook"];     if (mypreference == null)     {         viewdata["mypreference"] = "enter zipcode above more detailed information";         var tyi = (from s in db.profiles.orderbydescending(s => s.profileid).take(5) select s).tolist();     }     else     {         viewdata["mypreference"] = mypreference["name"];         string se = (string)viewdata["mypreference"];         var tyi = (from s in db.profiles.orderbydescending(s => s.profileid).take(5) se==s.state select s).tolist();     }      return view(); } 

the view:

@if (model.profile != null) {  foreach (var item in model.profile)  {   @item.city    } } 

when object reference not set instance of object error, line @if (model.profile != null) highlighted, tried this:

public list<profile>? profile { get; set; } 

but didn't work. ideas of how accept empty model in foreach or skip code @ runtime?

just noticed, you're calling view() not passing model, in view you're referencing model.profile. inevitably model null, , therefore has no profile property access. make sure you're passing model off view in return view(model) call.

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follow-up collections

i've found time have variable implements ienumerable<t>, it's best populate empty set on null value. say:

// no-nos (imho) ienumerable<string> names = null; // break kinds of                                   // access reliant on names being populated                                   // e.g. linq extensions  // better options: ienumerable<string> names = new string[0]; ienumerable<string> names = enumerable.empty<string>(); ienumerable<string> names = new list<string>(); 

unless checking if (variable != null && variables.count() > 0) every time want access it, make empty collection , leave @ that.

to come full-circle, long variable populated collection of sort (empty or populated) foreach shouldn't break. skip past code block , not output anything. if you're getting object null error, it's because variable empty , enumerator not retrieved.