Q5. What is an identifier? What is the identifier forming rule of C++?
Ans. Identifiers are fundamental building blocks of a program and are used as the general terminology for the names given to different parts of the program through variables, objects, classes, functions, arrays etc.
Identifier forming rule of C++ states the following:
An identifier is an arbitrarily long sequence of letters and digits. The first character must be a letter; the underscore (_) counts as a letter. Upper and lower-case letters are different. All characters are significant.