Naming Conventions in Java

Naming Conventions: We need to follow java naming conventions while writing java programs . In java we are recommended to follow the naming conventions while defining packages,classes,methods ,variables Interfaces and constants for better maintenance and readability of code.

Also see list of java keywords

i)For Packages: In java the prefix of a unique package name is always written in all-lowercase ASCII letters and should be one of the top-level domain names, like com, edu, gov, mil, net, org. Subsequent components of the package name vary according to an organisation’s own internal naming conventions.

Example:

                java.io

                java.lang

                java.util

                com.smartjavaguru

ii)For Classes and Interfaces: While defining classes and Interfaces we need to make sure the first letter starts with a Capital letter of the word or phrase of the name .The name may consists of combination of words in that case first letter of each word starts with a capital letter.

• Class names should be nouns, in mixed case with the first letter of each internal word capitalized. Interfaces name should also be capitalized just like class names.
• Use whole words and must avoid acronyms and abbreviations.

Example :  interface Vehicle {}

                    interface Sport{}

                    interface Bike{}

                   class Jeep implements Vehicle{ },

                   class Football implements Sport{}

                  class MoutainBike{}

iii)For Methods : In java all methods should be verbs, all method names starts with a lower case letter (first word first letter) and if the method name consists of more than one word then from the second word onward each word starts with a capital letter (Camel case)

Examples:

                    void sumOfTwoNums(int num1,int num2);

                    void speed(int increment);

                    void calculateInterest(int interestRate);

iv)Variables : In java variable names should be short and meaningful.Variable names should not start with underscore ('_') or dollar sign '$' chars. Single char names should be avoided except for temporary variables .All the variable names should be camelCase letters.

Example: 

                    int num=10;

                    int rate=2;

                    int speed=100;

v)Constants: In java all constants names should be all uppercase with words separated by underscores (“_”). There are various constants used in predefined classes like Float, Long, String etc.

Example: 

               int MIN_LENGTH=10;

              int MAX_SPEED=120;