implicit conversion in java operator +=

Question

I\'ve found that java compile has a non-expected behavior regarding assignment and self assignment statements using an int and a float.

The following code block illu

Answer 1

i believe that the explicit i+f fails because of Narrowing primitive conversion. While in the first case the conversion on the right side passes because it is done according to Compound Assignment rules.

Answer 2

http://docs.oracle.com/javase/specs/jls/se7/html/jls-15.html#jls-15.26.2

The Java Language Specification says:

A compound assignment expression of the form E1 op= E2 is equivalent to E1 = (T) ((E1) op (E2)), where T is the type of E1, except that E1 is evaluated only once.

So i += f is equivalent to i = (int) (i + f).