Simple Macro Substitution(#define) in c and cpp programming language

// C++ programming language
    #include<iostream>
    using namespace std;
    
    #define PI 3.1415
    
    int main(){
        cout<<"Value of PI : "<<PI<<endl;
        return 0;
    }

// c programming language
    #include <stdio.h>
    #define PI 3.145
    int main()
    {
        printf("Value of PI : %.3f", PI);
    
        return 0;
    }