How does long to int cast work in Java?

Question

This question is not about how a long should be correctly cast to an int, but rather what happens when we incorrectly cast it to an int.

So conside

Answer 1

The low 32 bits of the long are taken and put into the int.

Here's the math, though:

1. Treat negative long values as 2^64 plus that value. So -1 is treated as 2^64 - 1. (This is the unsigned 64-bit value, and it's how the value is actually represented in binary.)
2. Take the result and mod by 2^32. (This is the unsigned 32-bit value.)
3. If the result is >= 2^31, subtract 2^32. (This is the signed 32-bit value, the Java int.)