Constants in C++
Constants are identifiers whose associated value cannot be altered during the execution of the program.
#define VARIABLENAME value
const dataType VARIABLENAME = value;
You can either use #define preprocessor form to define a constant (at the preprocessor part of the code/beginning) or the const prefix to declare constant with a specific type (within the main code).
It is common practice to capitalize the entity of the variable name for constants.
dataType is the type (boolean, float, int, etc.) of the specified variable.
#define AGE 20
const int NEW_AGE = 21;