Is there such a thing as a chained NULL check?

Question

I have the following ugly code:

if (msg == null || 
    msg.Content == null || 
    msg.Content.AccountMarketMessage == null || 
    msg.Content.AccountMarke         


        

Answer 1

.NET Fiddle

As stated there is a plan to have c# 6.0 implement the ? operator to facilitate this process somewhat. If you cannot wait, I would suggest using a lambda expression and a simple helper function to solve this.

public E NestedProperty(T Parent, Func Path, E IfNullOrEmpty = default(E))
{
    try
    {
        return Path(Parent);
    }
    catch
    {
        return IfNullOrEmpty;
    }
}

This could be used int value = NestedProperty(blank,f => f.Second.Third.id); as shown in the demo below

program

public class Program
{
    public void Main()
    {
        First blank = new First();
        First populated = new First(true);

        //where a value exists
        int value = NestedProperty(blank,f => f.Second.Third.id);
        Console.WriteLine(value);//0

        //where no value exists
        value = NestedProperty(populated,f => f.Second.Third.id);
        Console.WriteLine(value);//1

        //where no value exists and a default was used
        value = NestedProperty(blank,f => f.Second.Third.id,-1);
        Console.WriteLine(value);//-1
    }

    public E NestedProperty(T Parent, Func Path, E IfNullOrEmpty = default(E))
    {
        try
        {
            return Path(Parent);
        }
        catch
        {
            return IfNullOrEmpty;
        }
    }
}

simple demo structure

public class First
{
    public Second Second { get; set; }
    public int id { get; set; }
    public First(){}
    public First(bool init)
    {
        this.id = 1;
        this.Second = new Second();
    }
}

public class Second
{
    public Third Third { get; set; }
    public int id { get; set; }
    public Second()
    {
        this.id = 1;
        this.Third = new Third();
    }
}

public class Third
{
    public int id { get; set; }
    public Third()
    {
        this.id = 1;
    }
}