Given a hexadecimal number as input, we need to write a program to convert the given hexadecimal number into equivalent decimal number.
Examples:
Input : 67 Output : 103 Input : 512 Output : 1298 Input: 123 Output: 291
We know that in hexadecimal number uses 16 symbols {0, 1, 2, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F} to represent all numbers. Here, (A, B, C, D, E, F) represents (10, 11, 12, 13, 14, 15).
The idea is to extract the digits of given hexadecimal number starting from right most digit and keep a variable dec_value. At the time of extracting digits from the hexadecimal number, multiply the digit with the proper base (Power of 16) and add it to the variable dec_value. At the end, the variable dec_value will store the required decimal number.
For Example:
If the hexadecimal number is 1A.
dec_value = 1*(16^1) + 10*(16^0) = 26
Below diagram explains how to convert hexadecimal number ( 1AB ) to equivalent decimal value:
Below is the implementation of above idea.
C/C++
// C++ program to convert hexadecimal to decimal #include<iostream> #include<string.h> using namespace std; // Function to convert hexadecimal to decimal int hexadecimalToDecimal(char hexVal[]) { int len = strlen(hexVal); // Initializing base value to 1, i.e 16^0 int base = 1; int dec_val = 0; // Extracting characters as digits from last character for (int i=len-1; i>=0; i--) { // if character lies in '0'-'9', converting // it to integral 0-9 by subtracting 48 from // ASCII value. if (hexVal[i]>='0' && hexVal[i]<='9') { dec_val += (hexVal[i] - 48)*base; // incrementing base by power base = base * 16; } // if character lies in 'A'-'F' , converting // it to integral 10 - 15 by subtracting 55 // from ASCII value else if (hexVal[i]>='A' && hexVal[i]<='F') { dec_val += (hexVal[i] - 55)*base; // incrementing base by power base = base*16; } } return dec_val; } // Driver program to test above function int main() { char hexNum[] = "1A"; cout << hexadecimalToDecimal(hexNum) << endl; return 0; } |
Java
// Java program to convert hexadecimal to decimal import java.io.*; class GFG { // Function to convert hexadecimal to decimal static int hexadecimalToDecimal(String hexVal) { int len = hexVal.length(); // Initializing base value to 1, i.e 16^0 int base = 1; int dec_val = 0; // Extracting characters as digits from last character for (int i=len-1; i>=0; i--) { // if character lies in '0'-'9', converting // it to integral 0-9 by subtracting 48 from // ASCII value if (hexVal.charAt(i) >= '0' && hexVal.charAt(i) <= '9') { dec_val += (hexVal.charAt(i) - 48)*base; // incrementing base by power base = base * 16; } // if character lies in 'A'-'F' , converting // it to integral 10 - 15 by subtracting 55 // from ASCII value else if (hexVal.charAt(i) >= 'A' && hexVal.charAt(i) <= 'F') { dec_val += (hexVal.charAt(i) - 55)*base; // incrementing base by power base = base*16; } } return dec_val; } // driver program public static void main (String[] args) { String hexNum = "1A"; System.out.println(hexadecimalToDecimal(hexNum)); } } // Contributed by Pramod Kumar |
Python3
# Python3 program to convert # hexadecimal to decimal # Function to convert hexadecimal # to decimal def hexadecimalToDecimal(hexval): # Finding length length = len(hexval) # Initialize base value to 1, # i.e. 16*0 base = 1 dec_val = 0 # Extracting characters as digits # from last character for i in range(length - 1, -1, -1): # If character lies in '0'-'9', # converting it to integral 0-9 # by subtracting 48 from ASCII value if hexval[i] >= '0' and hexval[i] <= '9': dec_val += (ord(hexval[i]) - 48) * base # Incrementing base by power base = base * 16 # If character lies in 'A'-'F',converting # it to integral 10-15 by subtracting 55 # from ASCII value elif hexval[i] >= 'A' and hexval[i] <= 'F': dec_val += (ord(hexval[i]) - 55) * base # Incrementing base by power base = base * 16 return dec_val # Driver code if __name__ == '__main__': hexnum = '1A' print(hexadecimalToDecimal(hexnum)) # This code is contributed by virusbuddah_ |
C#
// C# program to convert // hexadecimal to decimal using System; class GFG { // Function to convert // hexadecimal to decimal static int hexadecimalToDecimal(String hexVal) { int len = hexVal.Length; // Initializing base1 value // to 1, i.e 16^0 int base1 = 1; int dec_val = 0; // Extracting characters as // digits from last character for (int i = len - 1; i >= 0; i--) { // if character lies in '0'-'9', // converting it to integral 0-9 // by subtracting 48 from ASCII value if (hexVal[i] >= '0' && hexVal[i] <= '9') { dec_val += (hexVal[i] - 48) * base1; // incrementing base1 by power base1 = base1 * 16; } // if character lies in 'A'-'F' , // converting it to integral // 10 - 15 by subtracting 55 // from ASCII value else if (hexVal[i] >= 'A' && hexVal[i] <= 'F') { dec_val += (hexVal[i] - 55) * base1; // incrementing base1 by power base1 = base1 * 16; } } return dec_val; } // Driver Code static void Main() { String hexNum = "1A"; Console.WriteLine(hexadecimalToDecimal(hexNum)); } } // This code is contributed by mits |
PHP
<?php // PHP program to convert // hexadecimal to decimal // Function to convert // hexadecimal to decimal function hexadecimalToDecimal($hexVal) { $len = strlen($hexVal); // Initializing base value // to 1, i.e 16^0 $base = 1; $dec_val = 0; // Extracting characters as // digits from last character for ($i = $len - 1; $i >= 0; $i--) { // if character lies in '0'-'9', // converting it to integral 0-9 // by subtracting 48 from ASCII value. if ($hexVal[$i] >= '0' && $hexVal[$i] <= '9') { $dec_val += (ord($hexVal[$i]) - 48) * $base; // incrementing base by power $base = $base * 16; } // if character lies in 'A'-'F' , // converting it to integral // 10 - 15 by subtracting 55 // from ASCII value else if ($hexVal[$i] >= 'A' && $hexVal[$i] <= 'F') { $dec_val += (ord($hexVal[$i]) - 55) * $base; // incrementing base by power $base = $base * 16; } } return $dec_val; } // Driver Code $hexNum = "1A"; echo hexadecimalToDecimal($hexNum); // This code is contributed by mits ?> |
Output:
26
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