Below are some naming conventions of java programming language. They must be followed while developing software in java for good maintenance and readability of code. 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.
- 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 MountainBike implements Bicyle
interface Sport
class Football implements 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 newValue);
void speedUp(int increment);
void applyBrakes(int decrement);
3. Variables : Variable names should be short yet meaningful.
Variables can also start with either 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:
// variables 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 variables 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.
Examples:
com.sun.eng
com.apple.quicktime.v2
// java.lang packet in JDK
java.lang