SE450: Horstmann Chapter 1: Programming Style: Case Convention

SE450: Programming Style: Case Convention [49/53]

variables, fields and methods:
start with lowercase, use caps for new words:
```
name
sayHello
```
Classes:
start with uppercase, use caps for new words:
```
Greeter
ArrayList
```
Constants:
use all caps, underscores to separate words
```
PI
MAX_VALUE
```