Java identifiers

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Java identifiers

In java every name is called identifier such as,Class-name,Method-name,Variable-name…etc

Identifier Example

The example of identifier are listed below

public class Testing

{

public static void main(String[] args)

{

int a=10;

}

}

In Above Example there are 5 Identifier are used which listed below

Test     ->  Represent Class name

main   ->  Represent method name

String ->  Represent predefined class name

args   ->   Represent variable name

a        ->   Represent variable name

Rules and Regulation  to declare identifier in java

Follow the below steps to declare the identifier in java

Rule-1 

An identifier contains group of Uppercase & lower case characters, numbers, underscore& dollar

sign characters but not start with number.

int abc=10; --->valid

int _abc=30;--->valid

 int $abc=40;--->valid

int a-bc=50;--->not valid

 int 2abc=20; ---> Invalid

 int not/ok=100 --->invalid

Rule-2. 

Java identifiers are case sensitive of course java is case sensitive programming language. The

below three declarations are different & valid.

class Qa

{ 

int a=10;

Int A=20;

}

Rule-3. 

The identifier must be unique.(duplicates are not allowed)

Class A{}

Class A{}

Rule-4. 

It is possible to use predefined class names & interfaces names as a identifier but it is not

recommended.

class Qa

{

public static void main(String[] args)

{

 int String=10;

intSerializable=20;

System.out.println(String);

System.out.println(Serializable);

}

}

Rule-5

 It is not possible to use keywords as a identifiers.

int if=10;

 int try=20; //Invalid

Rule-6.

 There is no length limit for identifiers but is never recommended to take lengthy names because

it reduces readability of the code.