1. Java – Rules for Naming
Identifiers
By JavaWithUs ( www.javawithus.com )

2. Identifiers
Identifiers are symbolic names given to
classes, methods and variables.
Identifiers should follow certain rules.

3. Identifiers can contain capital
letters, small letters and numbers
Examples of Valid Identifiers :
car
anObject
myPRoGRAM123
bga45WD544 – The identifier need not be
meaningful

4. Identifiers can contain only the special
characters underscore _ and dollar $
Examples of Valid Identifiers :
_aName
Student_Class
Student_
_$_$$_
$ant
Examples of Invalid Identifiers :
Car>Class
%in

5. Identifiers should not start with a
number
Examples of Invalid identifiers :
1Aeroplane
1245

6. Identifiers should not contain
Spaces
Examples of Invalid identifiers :
Student class
A class

7. Keywords cannot be used as
identifiers
Examples of Invalid identifiers :
class
for
Examples of Valid identifiers :
For – for is a keyword but For is not a
keyword

8. Identifiers are case sensitive
Example :
Each of the following identifiers are different
Car
car
CAR
cAR
CaR

9. To learn more about identifiers in Java, read
the following articles :
http://www.javawithus.com/tutorial/the-hello-
world-program
http://www.javawithus.com/tutorial/naming-
conventions-for-identifiers
Learn Java through the tutorials on our
website.
http://www.javawithus.com/tutorial/

10. Presentation by
www.javawithus.com