Upto how long characters we can take identifiers?

class Identifier4
{
public static void main(String alt[])
{
int abcdefghijklmnopqrstuvwxyzabcdefg=30;
System.out.println(abcdefghijklmnopqrstuvwxyzabcdefg);
}
}
/*
O/P:- 30
Explanation :- There is no length limit of java identifiers but it never recommended
to take lengthy identifiers because it reduces readability of the code.
*/