Why don't Java's +=, -=, *=, /= compound assignment operators require casting?

Question

Until today, I thought that for example:

i += j;

Was just a shortcut for:

i = i + j;

But if we try this:<

Answer 1

Yes,

basically when we write

i += l; 

the compiler converts this to

i = (int)(i + l);

I just checked the .class file code.

Really a good thing to know