## C Programming Examples Tutorial Index

Converting hexadecimal to decimal is a fundamental concept in programming and computer science. This tutorial will guide you through writing an efficient C program that can convert any hexadecimal number to its equivalent decimal representation.

## What is Hexadecimal to Decimal Conversion?

Hexadecimal to decimal conversion involves transforming numbers from the hexadecimal system (base 16), which uses the digits 0-9 and letters A-F, to the decimal system (base 10). This conversion is essential because hexadecimal numbers are often used in low-level and systems programming.

## Algorithm for Hexadecimal to Decimal Conversion

1. Initialize Variables: Declare variables for storing the hexadecimal number as a string and the decimal equivalent as an integer.
2. Input Hexadecimal Number: Prompt the user to enter a hexadecimal number. Use `scanf()` to take the input.
3. Conversion Process: Implement a loop that iterates through each character of the hexadecimal string, converting it to the corresponding decimal value and accumulating the result.
4. Output Decimal Number: Display the converted decimal number using `printf()`.

## Code Example

A C Program for Hexadecimal to Decimal Conversion:

``````#include <stdio.h>
#include <string.h>
#include <math.h>

int main() {
char hex[17];
int decimal = 0, base = 1, length, i, value;

// Take user input for the hexadecimal number
scanf("%16s", hex);

length = strlen(hex);

// Conversion process
for(i = length - 1; i >= 0; i--) {
if(hex[i] >= '0' && hex[i] <= '9') {
value = hex[i] - '0';
} else if(hex[i] >= 'A' && hex[i] <= 'F') {
value = hex[i] - 'A' + 10;
}
decimal += value * base;
base = base * 16;
}

// Display the decimal number
printf("Decimal equivalent: %d\n", decimal);

return 0;
}
``````

Program Output:

For instance, inputting the hexadecimal number `1A3` will result in the program converting and displaying its decimal equivalent as `419`.

``````Enter a hexadecimal number: 1A3
Decimal equivalent: 419
``````

## Conclusion

Creating a C program for converting hexadecimal to decimal numbers offers insight into how computers process and display numbers. This tutorial provides the knowledge to build a program that accurately executes this conversion, broadening your understanding of hexadecimal and decimal systems in computer programming.