Question

I found out that in C# a+=1 is not equal to a = a+1.

For example, the following code compiles without any error:
byte b = 10;
b += 5;

while the following code has a compilation error:
byte b = 10;
b = b + 5;

Can somebody let me know why?

Answer 1

Because b + 5 becomes an integer ( Int32) ( mainly because there is possibility of overload)

And the compound assignment specification states below:

Otherwise, if the selected operator is a predefined operator, if the
return type of the selected operator is explicitly convertible to the
type of x, and if y is implicitly convertible to the type of x or the
operator is a shift operator, then the operation is evaluated as x =
(T)(x op y), where T is the type of x, except that x is evaluated only
once.