What is the operator precedence of C# null-coalescing (??) operator?

Question

I\'ve just tried the following, the idea being to concatenate the two strings, substituting an empty string for nulls.

string a=\"Hello\";
string b=\" World\         


        

Answer 1

Aside from what you'd like the precedence to be, what it is according to ECMA, what it is according to the MS spec and what csc actually does, I have one bit of advice:

Don't do this.

I think it's much clearer to write:

string c = (a ?? "") + (b ?? "");

Alternatively, given that null in string concatenation ends up just being an empty string anyway, just write:

string c = a + b;

EDIT: Regarding the documented precedence, in both the C# 3.0 spec (Word document) and ECMA-334, addition binds tighter than ??, which binds tighter than assignment. The MSDN link given in another answer is just wrong and bizarre, IMO. There's a change shown on the page made in July 2008 which moved the conditional operator - but apparently incorrectly!