Java Naming Conventions Overview

Consistent naming conventions make your code easier to read, understand, and maintain. Java has well-established guidelines for naming classes, methods, variables, constants, and packages. Following these conventions helps you and others quickly identify the role and purpose of each element in your code.

Class Names

• Use PascalCase: capitalize the first letter of each word;
• Choose clear, descriptive nouns or noun phrases;
• Avoid abbreviations and acronyms unless they are widely recognized.

Example: public class CustomerAccount { ... }

Method Names

• Use camelCase: start with a lowercase letter, capitalize each subsequent word;
• Use verbs or verb phrases that describe the action performed;
• Keep names concise but meaningful.

Example: public void processOrder() { ... }

Variable Names

• Use camelCase: start with a lowercase letter, capitalize each subsequent word;
• Choose descriptive names that indicate the variable’s purpose;
• Avoid single-letter names except for temporary variables in short blocks.

Example: double accountBalance = 0.0;

Constant Names

• Use UPPER_CASE: all letters uppercase, separate words with underscores;
• Use nouns for values that do not change;
• Declare constants with the final keyword.

Example: public static final int MAX_LOGIN_ATTEMPTS = 5;

Package Names

• Use all lowercase letters;
• Use your organization’s reversed domain name as a prefix;
• Separate words with periods;
• Avoid using underscores or hyphens.

Example: package com.example.account;

Following these naming conventions improves code quality and helps teams collaborate efficiently. Always choose names that clearly express the intent and function of each code element.

Good and Bad Naming Choices in Java

Good Naming Examples:

• userName for a variable holding a user's name;
• calculateTotalPrice() for a method that calculates the total price;
• OrderService for a class that manages orders;
• MAX_SIZE for a constant representing the maximum size;
• isActive for a boolean indicating if something is active.

Bad Naming Examples:

• x for a variable storing a user's name;
• doIt() for a method that performs a specific calculation;
• os for a class that manages orders;
• ms for a constant representing the maximum size;
• flag1 for a boolean indicating if something is active.

Following these guidelines helps you write code that is easier to maintain, understand, and extend.