In this post, we will check whether a number is Armstrong or not in C++ and will also print all Armstrong numbers from 1 to 1000.

An Armstrong number is that number in which sum of the nth power of each digit is equal to the original number, where n is the number of digits in the number. To check Armstrong number in C++, we will have to implement the following steps.

1. Input the number (`num`).
2. Count the number of digits in the number (`length`).
3. Sum the digits raised to the power `length` and store in `sum`.
4. Check if `sum == num`.
5. If YES then its Armstrong Number, Else not.

Let’s see the C++ source code.

output

## Armstrong Number in C++ Between 1 to 1000

We now know how to check Armstrong’s number in C++.

Now Let’s use the same logic of the above program to check each number from 1 to 100 and output it if its Armstrong.

output

We have created a separate function isArmstrong() which returns `true` if the passed number is armstrong else it returns `false`.

Depending on the incoming result from ‘isArmstrong()’ method we output the number i.e if the returned value is `True`.

Comment below if you have not understood any part of the code or you have any suggestions.