Identifiers and Keywords in C++

In a C++ program (i.e., a program written in C++ language), every word is either classified as an identifier or a keyword. Identifiers, as the name suggests, are used to identify or name various program elements such as variables, constants, functions etc. On the other hand, Keywords are a kind of reserved word which have standard, predefined meanings in C++. Now, let us discuss these concepts in details: Identifiers: As stated before, identifiers are names that are given to various program elements such as variables, constants, functions, arrays etc. There are certain rules regarding identifier names in C++, as stated below: Identifiers must consist of letters and digits, in any order, except that the first character must be a letter Both upper-case and lower-case letters are permitted, though common usage favours the use of lower-case letters for most types of identifiers. Upper-case and lower-case letters are not interchangeable i.e., an upper-case...