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Anicho
Anicho

Reputation: 2667

C# Object reference not set to an instance of an object

I have the following code:

public void SetUser(User user)
{
   string streetNumber = "";

   if (user.Address.StreetNo != null)
      streetNumber = user.Address.StreetNo.ToString();
   else
     streetNumber = "";
}

I get the ever popular

Object reference not set to an instance of an object.

issue.

Upvotes: 2

Views: 12752

Answers (5)

Curtis
Curtis

Reputation: 103338

public void SetUser(User user)
{
   string streetNumber = "";

   if (user != null && user.Address != null && user.Address.StreetNo != null) {
      streetNumber = user.Address.StreetNo.ToString();
   }
}

Taking into account @CKoenig's suggestion, the following throws an exception if the user or user.Address are null:

public void SetUser(User user)
{

   if (user == null) {
       throw new System.ArgumentNullException("user", "user cannot be null");
   }

   if (user.Address == null) {
       throw new System.ArgumentNullException("Address", "Address cannot be null");
   }
   
   string streetNumber = "";

   if (user.Address.StreetNo != null) {
      streetNumber = user.Address.StreetNo.ToString();
   }
}

Upvotes: 3

sll
sll

Reputation: 62484

public void SetUser(User user) 
{    
   string streetNumber = String.Empty;     

   if (user!= null 
       && user.Address != null 
       && user.Address.StreetNo != null)       
   {
         streetNumber = user.Address.StreetNo.ToString();    
   }
}

Upvotes: 2

k06a
k06a

Reputation: 18745

if (user != null
    && user.Address != null
    && user.Address.StreetNo != null)
{
    // ...
}

Upvotes: 1

Random Dev
Random Dev

Reputation: 52270

Check your stacktrace and:

  • user
  • user.Address
  • user.Address.StreetNo

with an if ... == null then ...

Upvotes: 1

cdhowie
cdhowie

Reputation: 168958

Either user is null, or user.Address is null. You need to test them too.

Upvotes: 2

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