we are doing print sum of variable and numbers with the help of addition operator.

#include <iostream>
using namespace std;

int main() {
  int sum1 = 100 + 50;        // 150 (100 + 50)
  int sum2 = sum1 + 250;      // 400 (150 + 250)
  int sum3 = sum2 + sum2;     // 800 (400 + 400)
  cout << sum1 << "\n";
  cout << sum2 << "\n";
  cout << sum3;
  return 0;
}

we are doing print sum of two numbers with the help of addition operator.

#include <iostream>
using namespace std;

int main() {
  int x = 100 + 50;
  cout << x;
  return 0;
}

We are doing create an object of class then called constructor automatically

#include <iostream>
using namespace std;

class MyClass {     // The class
  public:           // Access specifier
    MyClass() {     // Constructor
      cout << "Hello World!";
    }
};

int main() {
  MyClass myObj;    // Create an object of MyClass (this will call the constructor)
  return 0;
}

We are doing compare two integers numbers and print result of its.

#include <iostream>
using namespace std;

int main() {
  cout << (10 == 15);
  return 0;
}

We are doing call an function with multiple times.

#include <iostream>
using namespace std;

void myFunction() {
  cout << "I just got executed!\n";
}

int main() {
  myFunction();
  myFunction();
  myFunction();
  return 0;
}

We are doing access attributes of class and then modify it.

#include <iostream>
using namespace std;

class MyClass {   // The class
  public:         // Public access specifier
    int x;        // Public attribute (int variable)
};

int main() {
  MyClass myObj;  // Create an object of MyClass

  // Access attributes and set values
  myObj.x = 15;

  // Print values
  cout << myObj.x;
  return 0;
}