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C++ Exercises: Find the sum of digits of a given number

C++ For Loop: Exercise-10 with Solution

Write a program in C++ to find the sum of digits of a given number.

Pictorial Presentation:

C++ Exercises: Find the sum of digits of a given number

Sample Solution :-

C++ Code :

#include <iostream>
using namespace std;
int main()
{
    int num1, num2, r, sum=0;
    cout << "\n\n Find the sum of digits of a given number:\n";
    cout << "----------------------------------------------\n";
    cout << " Input a number: ";
    cin >> num1;
    num2 = num1;
    while (num1 > 0) 
    {
        r = num1 % 10;
        num1 = num1 / 10;
        sum = sum + r;
    }
    cout << " The sum of digits of " << num2 << " is: " << sum << endl;
}

Sample Output:

 Find the sum of digits of a given number:                             
----------------------------------------------                         
 Input a number: 1234                                                  
 The sum of digits of 1234 is: 10  

Flowchart:

Flowchart: Find the Greatest Common Divisor (GCD) of two numbers

C++ Code Editor:

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Previous: Write a program in C++ to find the Greatest Common Divisor (GCD) of two numbers.
Next: Write a program in C++ to find the sum of the series 1 + 1/2^2 + 1/3^3 + …..+ 1/n^n.

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C++ Programming: Tips of the Day

What is a smart pointer and when should I use one?

This answer is rather old, and so describes what was 'good' at the time, which was smart pointers provided by the Boost library. Since C++11, the standard library has provided sufficient smart pointers types, and so you should favour the use of std::unique_ptr, std::shared_ptr and std::weak_ptr.

There was also std::auto_ptr. It was very much like a scoped pointer, except that it also had the "special" dangerous ability to be copied - which also unexpectedly transfers ownership.

It was deprecated in C++11 and removed in C++17, so you shouldn't use it.

std::auto_ptr<MyObject> p1 (new MyObject());
std::auto_ptr<MyObject> p2 = p1; // Copy and transfer ownership. 
                                 // p1 gets set to empty!
p2->DoSomething(); // Works.
p1->DoSomething(); // Oh oh. Hopefully raises some NULL pointer exception.

Ref : https://bit.ly/3mc9GHE