Java Identifiers

Java Identifiers

Legal identifiers must be composed of only Unicode characters, numbers, currency symbols, and connecting characters (like underscores).

• Identifiers must start with a letter, a currency character ($), or a connecting character such as the underscore ( _ ). Identifiers cannot start with a number!

• After the first character, identifiers can contain any combination of letters, currency characters, connecting characters, or numbers.

• In practice, there is no limit to the number of characters an identifier can contain.

• You can't use a Java keyword as an identifier. "Complete List of Java Keywords" lists all of the Java keywords.

• Identifiers in Java are case-sensitive; foo and FOO are two different identifiers.

Examples some legal identifiers:
int _a;
int $c;
int ______2_w;
int _$;
int this_is_a_very_detailed_name_for_an_identifier;

The following are illegal identifiers
int :b;
int -d;
int e#;
int .f;
int 7g;