Changing Between Types

We would like to :

Consider this code

public static void main(String[] args){
    int anInt = 3;
    float aFloat = anInt;

We get

 Zamp3.java:7: error: incompatible types: possible lossy 
 conversion from float to int

To convince it to compile, we need to cast or typecast from one type to another.

By the way, when the compiler does it, we call it coercion.

In java we have a numeric type hierarchy:

```
byte short int long float double 
```
To move from the left to the right, the compiler is happy and will coerce
- This is called widening, because we are (mostly) moving from a smaller number of bits to a larger number of bits.
- Roundoff can occur, but we know about.
To move from the right to the left, we must cast.
- This is called narrowing and can lead to problems.
- IE totally wrong answers.

But what happens?

Try setting aFloat to pow(2, 32)
Try setting aFloat to be 3.99
- Truncates by default.
- So (int) (aFloat + .5) will round properly

In the end, we have to cast, but be careful.