#define c++ example

Example 1: #define in cpp

// The #define preprocessor directive creates symbolic constants
#include <iostream>
using namespace std;

#define CONSTANT 2.71828

int main () {
   cout << "Declared constant: " << CONSTANT << endl; 

   return 0;
}

Example 2: c++ what is #define

// #define is a macro that lets you use an alias name to
// make code more readable. During C++'s preproccessing stage, your macro
// will be replaced with the suitable code needed for proper compiling. 

#include <iostream>
// used to define constants, types, functions and more....

#define SIZE 5 
#define MacroInt int 
#define getmax(a,b) ((a)>(b)?(a):(b))

int main(){
  	MacroInt myIntAsMacro = 7;
    std::cout<< getmax(SIZE, myIntAsMacro); // will return 7
}