Naming Conventions in Java

Naming Conventions in Java

As the movies are rated G, PG, U, A depending on the age restriction and by just gazing through the rating our parents decide the movie to watch together, or a book with diffrent labels to keep track of the sections and just by seeing them we know what they represent, the same labeling method has been introduced by Java team to diffrenciate variables, methods, classes, constants etc.. and we will be going through them all here.

Type	Naming Convention	Example
Variables	Must start with a lower case and every other word capitalized	int counter;
Constants	Must all be upper case and _ for diffrenciating every other word	final int MAX_HEALTH = 100;
Methods	Must start with a lower case and every other word capitalized. can be distingiused from the variable by the () next to the method name	void printNum(){..}
Class	Must start an upper case letter and every other word must be capitalized	class HelloWorld{..}
Interface	Must start an upper case letter and every other word must be capitalized	interface ActionListner{..}

1. Packages

   A package must all be in lowercase letters example java.awt and as it represents a group of classes and interface in case another developer wants to import your package this nameing convention will be helpful for him to proceed further without worring about the case in the name for example java.awt is easier to recall than jAvA.AwT so it avoids the un necessary confusion.
   
   here is an example
   package myown.io import java.io

2. Constants

   A constant variable must be only completly upper case and to diffrenciate the words we can use underscores(_), there are some pre-buid constants such as MAX_VALUE , MIN_VALUE in the Number's subclasses etc..
   
   here is an example
   final int WORKING_HOURS = 6;

3. Variables

   A variable is a refrence of an object or a value of any datatype and the name must start with lowercase and every other word must be capitalized and this method is called cammel casing for example int ageOfPet = 1; or if its only one word then int age = 10; so anytime you see this naming convention then assume its a variable unless except with an exception that we will see in the methods.
   
   here is an example int age = 6; age = 12; System.out.println(age);

4. Methods

   The naming convention is the same as the variable, must start with the lowercase and every other word must be capitalized or in other words must be a camel case word but I know you are asking in your mind "if both methods and variables have the same naming convention whats the whole point?"  Well, the thing is methods always have brackets next to them example sum(5+5) or public static void main(String[], arg) so as you can see even though they have the same naming convention they both can be easily differentiated.
   
   here is an example
   void printNum(int a)
{
System.out.println(a)
}


5. Class

   A class must start with a capital letter and every other word capitalized for example class HelloWorld {} or class Hello{} so just capitalize all the words, the same naming convention for the abstract classes as well.
   
   here is an example
   class HelloWorld
{
....
}


6. Interface

   An Interface must be named same as the classes naming convention, The first letter must be capitalized and all other words must be capitalized as well for example interface ActionListner{}
   
   here is an example
   interface ActionListner
{
....
}


Other Important Note

• Symbols such as $ or _ etc can be used if you want but everything must start with an alphabet
• Not following the naming convention will not throw compile time error.