The names of variables, functions, arrays, and other user-defined data types that the programmer has generated are referred to by C++ identifiers in programmes. They are a language’s fundamental requirements. There are certain guidelines for naming the IDs in each language.
There are several types of identifiers in C++:
Variable names: used to keep values in memory
Function names: used to specify operations and carry out tasks
Class names: used for object creation and class definition
Object names: examples of classes
Enumeration constants: in data types that are enumerated
Label names: employed in program to identify statements
Namespaces: used to arrange code and eliminate naming conflicts.
Keyword in C++
The reserved words that are predetermined and have a certain meaning are called keywords. Any program me statement can be defined with the use of keywords. In terms of C language, there are 32 keywords. Among the keywords are double, int, auto, char, break, and a few others.
Example:
#include<iostream>
using namespace std;
int main(){
  // Using Initilazation Const Keyword
  const int x = 20;
  cout<<"Value is: "<<x;
return 0;
}
Output is:
Value is: 20
Keyword vs identifier
| S.No. | Keyword | Identifier |
| 1 | Reserved words with specialized definitions and distinct connotations are called keywords. Any program me statement can be defined with the use of keywords. | An identifier is a specific name that a programmer creates to define a class, function, variable, or structure. |
| 2 | A lowercase letter starts a keyword. | The initial character in the identification may start with underscores, lowercase letters, or capital letters. |
| 3 | It describes the kind of thing. | It categories the entity’s name. |
| 4 | Only characters in the alphabet are allowed. | It may contain underscores, digits, and characters from the alphabet. |
| 5 | It needs to be written in lowercase. | It can have capital and lowercase letters. |
| 6 | It is useful for specifying a specific feature of a computer language. | It is useful for finding the entity’s name. |
| 7 | Keywords include double, int, auto, char, break, and more. | Examples of identifiers are test, count1, high-speed, etc. |