Question

I saw some code written by another developer that looks something like this:

var stringBuilder = new StringBuilder();

if(stringBuilder == null)
{
    // Log memory allocation error
    // ...
    return;
}

(It is ALL over the place in the code )

Question 1:
Would that error logging code even get called? If there was no memory, wouldn’t an System.OutOfMemoryException be thrown on that first line?

Question 2:
Can a call to a constructor ever return null?

Answer 1

You’re correct, and that code is wrong. It will throw OutOfMemoryException on a failure. This is clear in the documentation:

“If the new operator fails to allocate
memory, it throws the exception
OutOfMemoryException.”

Constructors don’t return anything, let alone null. They manipulate an object that’s already been allocated.