In C#, what does '|=' do?

Question

I can't seem to Google it - doesn't appear to like the syntax in the search string. Thank you for the help.

Answer 1

This is a bit wise assignment. It's roughly shorthand for the following

x |= y;
x = x | y;

Note: It's not truly the above because the C# spec guarantees the side effects of x only occur once. So if x is a complex expression there is a bit of fun code generated by the compiler to ensure that the side effects only happen once.

Method().x |= y;
Method().x = Method().x | y;  // Not equivalent

var temp = Method();
temp.x = temp.x | y;  // Pretty close

Answer 2

The expression a |= b is equivalent to the assignment a = a | b, where | is the bitwise OR operator.*

^{* Not entirely, but close enough for most purposes.}