Naming conventions in java for variables | file naming conventions

Naming Conventions in Java

   

Java uses CamelCase as a practice for writing names of methods, variables, classes, packages and constants.

Camel case in Java Programming : It consists of compound words or phrases such that each word or abbreviation begins with a capital letter or first word with a lowercase letter, rest all with capital.

 

java naming convertion

     1.    Classes and Interfaces :

·         Class names should be nouns, in mixed case with the first letter of each internal word capitalised. Interfaces name should also be capitalised just like class names.

·         Use whole words and must avoid acronyms and abbreviations.

Examples:

interface Bicycle

class MountainBile implement Bicycle

interface Sport

class Football implement Sport

    2.    Methods :

·         Methods should be verbs, in mixed case with the first letter lowercase and with the first letter of each internal word capitalised.

Examples:

void changeGear(int new Value);

void speedup(int increment);

void applyBrakes(int decrement);

    3.    Variables : Variable names should be short yet meaningful.

·         Should not start with underscore(‘_’) or dollar sign ‘$’ characters.

·         Should be mnemonic i.e, designed to indicate to the casual observer the intent of its use.

·         One-character variable names should be avoided except for temporary variables.

·         Common names for temporary variables are i, j, k, m, and n for integers; c, d, and e for characters.

Examples:

//variable for MountainBike class

int  speed=0;

int  gear=1;

   4.    Constant variables:

·         Should be all uppercase with words separated by underscores (“_”).

·         There are various constants used in predefined classes like Float, Long, String etc.

Examples:

Static final int MIN_WIDTH=4;

//Some Constant variable used in predefined Float class

public static final float POSITIVE_INFINITY=1.0f/0.0f;

public static  final float NEGATIVE_INFINITY=1.0f/0.0f;

public static final float NaN =0.0f/0.0f;

    5.    Packages:

·         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:

com.sum.eng

com.apple.quicktime.v2

//java.lang packet in JDK

Java.lang