Identifiers In Java

   Java Identifiers 

Any name in java consider as identifier which is used for identification purpose. 

•  Identifier can be class name 
• Identifier can be Label name
• Identifier can be Variable name 

Allowed Character in java identifiers are : 

• A to Z
• a to z
• 0 to 9
• _underscore Symbol

$Dollor Symbol also can use: 

• Eg : total_number

Identifier Cant start with Number : 

• Eg ;00122value

 We can use numbers after the any letters:

• Eg : suresh123

Java identifier are Case Sensitive: 

Eg : 

• int number =10;
• int Number = 10;
• int NUMBER =10;

 These three variables are different because java is case Sensitive 

No length restriction in identifier in java :

• Eg : int Sureshkumarbajeer = 10; (Its valid)

We can't use reserved in java identifiers :

Eg : int if =10;    String Case = "Suresh";

if we use reserved word like (if ) then we will get compile time error. 

We can use pre define class as identifiers : 

int String = 10;  (It's Valid)

Valid Declaration in Java : 

int Int 10;

String string ="Suresh";

int total =10;

int _totoal = 10;

int $cash =10;

-> In java version 9  _Underscore is a keyword . Cannot be used as identifier in the java . 

-> But we can use _Underscore as the identifier till 8.0 version.