Java Identifiers - Best Practices and Naming Conventions

Learn about Java identifiers, the unique names used to identify variables, methods, and other elements in Java programs. Discover best practices for choosing descriptive and maintainable names in your code.

Java Identifiers

All Java variables must be identified with unique names called identifiers.

Identifiers can be short names (like x and y) or more descriptive names (age, sum, totalVolume).

Note: It is recommended to use descriptive names to create understandable and maintainable code:

Example:

// Good

int minutesPerHour = 60;

// OK, but not so easy to understand what m actually is

int m = 60;

The general rules for naming variables are:

  • Names can contain letters, digits, underscores, and dollar signs
  • Names must begin with a letter
  • Names should start with a lowercase letter, and cannot contain whitespace
  • Names can also begin with $ and _ (but we will not use it in this tutorial)
  • Names are case-sensitive ("myVar" and "myvar" are different variables)
  • Reserved words (like Java keywords, such as int or boolean) cannot be used as names
Example
// Good
int minutesPerHour = 60;

// OK, but not so easy to understand what m actually is
int m = 60;