Identifier Literals and Constant in Java

Identifier:-

The name we choose for a variable is called an identifier. An identifier can be of any length but it must begin with an alphabet, underscore or ‘$’  the rest of an identifier can include digit also.
Operators and spaces are not allowed in an identifier. We can’t use java keyword also. Keywords are words that are an essential part of java. Java is case sensitive language.

Name of class should start with capital letter only.

e.g.
max, Max, maX, MAX all are different
ab$cd         right
ab_123       right
_abcd         right
ab+cd        wrong
ab@cd      wrong
_ab123      right
123ab       wrong
while         wrong it is a keyword
While         right

Literals:-

Explicit data values that appear in our program are called literals.
int a = 25;      here a is variable and 25 is literal.

Constant:-

If a variable is declared final its value can’t be changed
final int MAX=100;                 constant name should be in capitals only.