Java For Dummies Quick Reference

Identifiers

An identifier is a word that you make up to associate a name with a Java programming element, such as a variable, field, parameter, class, or method.

Here are the rules for creating identifiers:

Identifiers are case-sensitive. As a result, SalesTax and salesTax are distinct identifiers.

Identifiers can be made up of uppercase or lowercase letters, numerals, underscore characters (_), and dollar signs ($). Thus, you can have identifier names such as Port1, SalesTax$, and Total_Sales.

All identifiers must begin with a letter. Thus, a15 is a valid identifier, but 13Unlucky isn’t (because it begins with a numeral).

An identifier can’t be the same as any of the Java keywords listed earlier in this part. Thus, you can’t create a variable named for or a class named public.

The Java language specification recommends that you avoid using dollar signs in names you create because code ...