Question

Example

public class ClassA
{
    public ClassA(string someString){}
}

public class ClassB : ClassA
{
    public ClassB(string someString):base(someString.ToLower()){}
}

I call the inherited ClassB constructor. I pass in a null. ToLower() throws an exception on a null. I want to check for a null before that happens. How can I do this?

Answer 1

Simple. Using null-coalescing operator:

public ClassB(string someString) : 
    base((someString ?? "").ToLower())
{
}

Or using ternary operator

public ClassB(string someString) : 
    base(someString == null ? "" : someString.ToLower())
{
}

Better yet, I’d suggest you to add a no-arg constuctor to ClassB, which will call base(string.Empty).