In this shot, we will discuss how to convert a number from binary to decimal in C++.

When we convert a binary number to a decimal number, we multiply each digit by ($2^n$). 

Let's look at the below image to understand how this conversion works.

In the above image, the binary number is multiplied by $2^n$ from the right side to the left side with the increasing $n$ that is $2^0$, $2^1$,$2^2$ and so on.
The value of binary number `10110` in decimal form is `22`.

# Code

Let's look at the below code snippet to understand this better.

#include <iostream>
using namespace std;

int main() {
  int decimal = 0, binary, remainder, product = 1;
  cin >> binary;
  while (binary != 0) {
    remainder = binary % 10;
    decimal = decimal + (remainder * product);
    binary = binary / 10;
    product *= 2;
  }
  cout << "The number in the decimal notation is: " << decimal ;
  return 0;
}

> *Enter a binary number above in the input section.*
## Explanation

* In line 5, we initialize the variables `decimal`, `binary`, `remainder`, and `product`.

* In line 6, we take `binary` as input.

* In lines 7 to 12, we initialize a `while` loop. In the loop, we make the required calculations, as discussed in the above illustration, to convert the binary number to its decimal equivalent.

* In line 13, we print the output, i.e., the decimal equivalent of the binary number.


How to convert a number from binary to decimal in C++

Multiply each binary digit by $2^n$ and sum for conversion to decimal in C++.