Program for decimal to hexadecimal conversion in C++

Given with a decimal number as an input, the task is to convert the given decimal number into a hexadecimal number.

Hexadecimal number in computers is represented with base 16 and decimal number is represented with base 10 and represented with values 0 - 9 whereas hexadecimal number have digits starting from 0 – 15 in which 10 is represented as A, 11 as B, 12 as C, 13 as D, 14 as E and 15 as F.

To convert a decimal number into a hexadecimal number follow the given steps −

• Firstly divide the given number with the base value of conversion number e.g. dividing 6789 by 16 because we need to convert 6789 into a hexadecimal numbers which have base 16 and then obtain a quotient and store it. If the remainder is between 0-9 store them as it is and if the remainder lies between 10-15 convert them in their character form as A - F
• Divide the obtained quotient with the base value of hexadecimal number which is 16 and keep storing the bits.
• Keep doing right shift to the stored bits
• Repeat the step until the remainder left indivisible

Given below is the pictorial representation of converting a decimal number into a hexadecimal number.

Example

Input-: 6789
   Divide the 6789 with base 16 : 6789 / 16 = 5 (remainder) 424(quotient)
   Divide quotient with base: 424 / 16 = 8(remainder) 26(quotient)
   Divide quotient with base: 26 / 16 = 10(remainder) 1(quotient)
   Now reverse the remainder obtained for final hexadecimal value.
Output-: 1A85

Algorithm

Start
Step 1-> Declare function to convert decimal to hexadecimal
   void convert(int num)
      declare char arr[100]
      set int i = 0
      Loop While(num!=0)
         Set int temp = 0
         Set temp = num % 16
         IF temp < 10
            Set arr[i] = temp + 48
            Increment i++
         End
         Else
            Set arr[i] = temp + 55
            Increment i++
         End
         Set num = num/16
      End
      Loop For int j=i-1 j>=0 j—
         Print arr[j]
Step 2-> In main()
   Set int num = 6789
   Call convert(num)
Stop

Example

 Live Demo

#include<iostream>
using namespace std;
//convert decimal to hexadecimal
void convert(int num) {
   char arr[100];
   int i = 0;
   while(num!=0) {
      int temp = 0;
      temp = num % 16;
      if(temp < 10) {
         arr[i] = temp + 48;
         i++;
      } else {
         arr[i] = temp + 55;
         i++;
      }
      num = num/16;
   }
   for(int j=i-1; j>=0; j--)
   cout << arr[j];
}
int main() {
   int num = 6789;
   cout<<num<< " converted to hexadeciaml: ";
   convert(num);
   return 0;
}

Output

IF WE RUN THE ABOVE CODE IT WILL GENERATE FOLLOWING OUTPUT

6789 converted to hexadeciaml: 1A85

Sunidhi Bansal

Published on 18-Oct-2019 11:47:51