Java offers the following conventions for writing identifiers.
An identifier begins with a letter, an underscore or a currency symbol (e.g. $ ). This initial letter can be followed by any number of letters, digits, underscores or currency symbols.
The prefix of a unique package name is written in all-lowercase ASCII letters and should be one of the top-level domain names. Subsequent components of the package name vary according to an organization's own internal naming conventions.
Classes and interfaces should be nouns, in mixed case with the first letter of each internal word capitalized.
Methods should be verbs, in mixed case with the first letter lowercase, with the first letter of each internal word capitalized
i: run ( -- )
i: runFast ( -- )
: getBackground ( -- )
Variables are written in mixed case with a lowercase first letter. Variable names should not start with underscore _ or dollar sign $ characters, even though both are allowed.
Standard types are written in lower case. Class types are written like classes, the first letter is capitalized.
The names of constants should be all uppercase with words separated by underscores.
static final int MIN_WIDTH