Question

Had a coworker ask me this, and in my brain befuddled state I didn’t have an answer:

Why is it that you can do:

string ham = 'ham ' + 4; 

But not:

string ham = 4; 

If there’s an implicit cast/operation for string conversion when you are concatenating, why not the same when assigning it as a string? (Without doing some operator overloading, of course)

Answer 1

When concatenating the compiler turns the statement 'ham' + 4 into a call to String.Concat, which takes two object parameters, so the value 4 is boxed and then ToString is called on that.

For the assignment there is no implicit conversion from int to string, and thus you cannot assign 4 to a string without explicitly converting it.

In other words the two assignments are handled very differently by the compiler, despite the fact that they look very similar in C#.