C++

Main function can be used without return statement. It by default includes return 0

• Think operators as functions like: cout << "Hello" << endl; as cout.print("Hello).print(endl);

Headers and Namespaces

Headers and Preprocessor Directives

• Namespace:

  // sum.h
  #pragma once
  
  namespace customSum {
    int sum(int a, int b);
  }
  
  // sum.cpp
  namespace customSum {
    int sum(int a, int b) {
      return a + b;
    }
  }
  
  
  // Main file
  #include "sum.h"
  
  int main() {
    cout << customSum::sum(10, 20);
  
    return 0;
  }

Arrays

#include <iostream>
#include <stdio.h>

using namespace std;

int main()
{
    int A[5] = {1, 5, 5};

    for (int i = 0; i < 5; i++)
    {
        cout << A[i] << endl;
    }

    // FOR EACH LOOP
    for (int x : A)
    {
        cout << x << endl;
    }

    cout << sizeof(int) << endl;
    cout << sizeof(A) << endl;
    printf("Completed");

    return 0;
}

• Size of an array can be dynamically provided, but during declaration the items cannot be initialized

int main()
{
    int n;
    cout << "Enter size";
    cin >> n;
    int A[n];

    return 0;
}

Virtual Functions

• Dynamic Dispatch
• V Table

Pure Virtual Functions are similar to Interface or Abstract Class