1.2.9 Capitalization and Commenting Conventions

By convention, Java programs are written entirely in lower case characters with three exceptions.

• The first letter of class names are capitalized to distinguish class names from member names.
• The names of constant fields are written entirely capital letters. For example, the built-in Java class Integer includes the constant static fields MIN_VALUE and MAX_VALUE. The underscore character "_" is used as a separate between words in a compound constant name, but not in other compound identifiers.
• The first letter in each word in a compound identifier (other than a constant) after the first are capitalized. For example, the built-in Java class Object includes a method called toString() that we will discuss later. The capital S signifies the beginning of a word within the compound name toString().

These conventions are not enforced by Java compilers, but it is considered bad style to violate them. A related convention is to never use the special character $ in a name; this character is reserved for the use of the Java compiler. Unfortunately, most Java compilers do not enforce this convention.

Java relies on commenting conventions similar to those in C++. A comment that is confined to a single line begins with the character sequence // and ends at the end of the line. Longer comments must be enclosed between the opening ``bracket'' /* and ``closing'' bracket */. Examples of both form of comments appear in Section 1.5.

Finger Exercise: add both forms of comment to the Conversions class from the preceding exercise.