Identifier.java

//method name
//variable name 
//label name
// class name

class Identifier{
    public static void main(String[] args) {
        int a = 10;
        int a100 =100;
        int $100 =100;
        int _fnv = 200;
        // int 1abc =200; not allowed

        // in java identifier does not have limit so you can name as long as you want 
        int aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa =100;


        // predifined class name can be a  variable name also

        int String = 200;
        int Runnabble =500;
        char Integer = 'a';

    }
}