JAVA IDENTIFIERS

JAVA IDENTIFIERS

A name in java program is called identifier which can be used for identification purpose it can be method name,variable name,class name,level name .

class test

{
public static void main(String[]args)

{

int x=10;

}

}

1-class -class name

2-main-name method

3-string-predefined class

4-args-Array

5-x-variable 

Rules For Defining java Identifiers-

The only allowed character in java given below-

Rule-1

a to z

A to Z

0 TO 9

$

-

EXAMPLE-

total-number (right)

total # (Wrong)

Rule-2

 

identifiers can't starts with the digit

Example-

total123 (right)

123total (Wrong)

Rule-3

Java identifiers are case sensitive of course java language it self is treated  case sensitive programming language .

Example-

class test{

int number=10;

int Number=20;

int NUMBER=30;

}

Rule-4

There is no length limit for java identifiers but it is not recommended to take too lengthy identifiers .

Rule-5

We cant use reserved word about as identifiers

Example-

int x=10;  (right)

int if=120; (wrong)

All Predefined java class name or , interface name we can use as identifiers .even though it is valid but it is not a good  programming practice because it reduce readability and creates confusion .

Which have the following are valid java identifiers

total_nuimber  (right)

total#  (wrong)

123total (wrong)

ca$h (right)

-$-$-$-$-$ (right)

all@hands (wrong)