Decimal To Binary Conversion Program Example using CPP

Source Code:

#include <iostream>
using namespace std;

/*
Decimal To Binary is converted Using Remainder Method.

*/

int main(int argc, char** argv) {
    
    // Declaration Statements
    int ar[10]; // used to store binary digits
    int num;  // used to store decimal input
    int i;  // counter variable
    
    cout<<"Enter Decimal Number: ";
    cin>>num;
    
    // Binary conversion processing
    for(i = 0; num > 0;  i++) {
        /* finding Remiainder by 2.
           because base of binary numbers
           is 2
        */
        ar[i] = num % 2; // Storing remainder in array
        num = num / 2;   // reducing number by 2
    }
    
    i--;  // returning counter variable to last digit index.
    //printing equivalent binary number
    cout<<"Equivalent Binary Number is: ";
    while( i >= 0) { // loop will iterate until first index
        cout<<ar[i];   // displaying array elements
        i--;  // printing array from right to left.
    }
    
    return 0;
}

Output:

Working:

In this program example we are going to convert a decimal number taken by user as input. To get equivalent binary number we have to repeat the following steps.

1. Take remainder of given number
2. Put this remainder in successive array index
3. Divide number by 2.
4. Repeat from Step 1

To complete the process of conversion first of all we declare an array of size 10. The size of array may be diffeent according to the required processing of decimal number. If we want to convert large decimal numbers then we will have to increase the size of array.

The list of variables used in this program is as provided.