## How to convert a decimal value to hexadecimal:

Decimal numbers are numbers with base value *10* and hexadecimal numbers are numbers with base *16*. Since hexadecimal is a base *16* number format, *0 to 9* are represented by *0 to 9* and *10 to 15* are represented by *A to F*.

### How to convert decimal to hexadecimal:

To convert a *decimal* value to *hexadecimal* value, we need to keep dividing the decimal value by *16* until we reach *0*. On each step, we will pick the remainder. Using the remainders, we can build the final *hexadecimal conversion*.

For example, Letâ€™s try to convert *2000* to hexadecimal:

- Divide
*2000*by*16*,*2000/16 = 125*, remainder -*0* *125/16 = 7*, remainder -*13**7/16 = 0*, remadinder -*7*

We have the remainders : *7, 13 and 0* from bottom to top. The hexadecimal value of *13* is *D*. So, the hexadecimal value of *2000* is *7D0*.

### Algorithm for a C++ program to convert a decimal value to hexadecimal:

Since we have both numbers and characters to store for a *hexadecimal* value, we need to store them in a *character array*. For that, we need to convert the integer value to *character* and it can be done by storing the *ASCII* values. *ASCII* value of *0* is *48* and *ASCII* value of *A* is *65*.

So, if the current remainder is less than *10*, we can add it to *48* and store that in the character array. And, if it is more than *10*, we can add it to *65* to convert the value to the character that we want and store that value in the character array.

For example, if it is *12*, we will add *55* and it will become *67*, which is *ASCII* of *C*.

### C++ program to convert a decimal value to hexadecimal:

Below is the complete *C++* program to convert *decimal* to *hexadecimal*:

```
#include <iostream>
#include <algorithm>
using namespace std;
string decimalToHexa(int no)
{
char hexa[100];
int position = 0;
while (no != 0)
{
int currentValue = no % 16;
if (currentValue < 10)
{
hexa[position] = currentValue + 48;
position++;
}
else
{
hexa[position] = currentValue + 55;
position++;
}
no = no / 16;
}
string hexa_string = string(hexa);
reverse(hexa_string.begin(), hexa_string.end());
return hexa_string;
}
int main()
{
cout << decimalToHexa(2000) << endl;
}
```

Here,

*decimalToHexa*method is used to convert a decimal value to*hexadecimal*. This method takes one*integer*value as argument and returns one*string*i.e. the hexadecimal value as string.- Inside
*decimalToHexa*, we are using a*while*loop to keep dividing the number by*16*. The result is put in a different array called*hexa*. - Once the
*while loop*is completed, the result is converted to an array using*string()* - The result, i.e. the values are in reverse order. So, we used
*reverse()*function to reverse the result string. - This string is returned back.

If you run the above program, it will print the below output:

`7D0`

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