keywords and Identifiers

C++ Identifiers

C++ identifiers used in a program refer to the name of the programmer's constructed variable, function, array, or other user-defined data types. They are the fundamental necessity of every language, and each language has its own identification rules.

Some naming rules are common in both C and C++. They are as follows:

  • Only letter characters, numbers, and underscores are permitted.
  • Unable to start a digit identification name, i.e., alphabetical the initial letter. We can use letters, numbers, or underscores after the initial letter.
  • In C++, letters are distinguished from uppercase and lowercase. We can therefore argue that C++ is a case-sensitive identification.
  • Unable to use as a variable name a declared keyword.

The most significant difference between C and C++ is the variable's longitudinal limit. ANSI C++ only considers the first 32 characters in the name, but the length does not limit the ANSI C++.

The constants are the identifiers that do not change throughout program execution to the fixed value. Both C and C++ offer different literal constants and have any placement for the memory. The literal constants are, for instance, 123, 12.34, 037, 0X2, etc.

What are the keywords?

Keywords are those words reserved for the compiler which have a particular significance. They are for a purpose dedicated for which identifiers cannot be used. For example, the predefined words for 'for,' 'break,' 'while,' 'if, and others' are those terms with a comment previously known to the compiler. The word for the word is predetermined. Instead, the identification is the names defining variables, functions, arrays, objects, and classes by programmers for the pieces of the program.

data type