给定一个十六进制数作为输入，我们需要编写一个程序将给定的十六进制数转换为等效的十进制数。
例子：
Input : 67
Output: 103
Input : 512
Output: 1298
Input : 123
Output: 291我们知道十六进制数字使用16个符号{0、1、2、4、5、6、7、8、9，A，B，C，D，E，F}表示所有数字。在此，(A，B，C，D，E，F)表示(10、11、12、13、14、15)。
这个想法是从最右边的数字开始提取给定十六进制数字的数字，并保留变量dec_value。从十六进制数字中提取数字时，将数字乘以适当的底数(16的幂)，然后将其添加到变量dec_value中。最后，变量dec_value将存储所需的十进制数字。
例如：如果十六进制数为1A。
dec_value = 1 *(16 ^ 1)+ 10 *(16 ^ 0)= 26
下图说明了如何将十六进制数(1AB)转换为等效的十进制值：
以下是上述想法的实现。
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));
}
}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 mitsPHP
= 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
?>Javascript
Java
// Java program to convert hexadecimal to decimal
import java.io.*;
class GFG {
public static int HexToDec(String n)
{
return Integer.parseInt(n, 16);
}
public static void main(String[] args)
{
String n = "1A";
System.out.println(HexToDec(n));
}
}Python3
# Python program to convert hexadecimal to decimal
def HexToDec(n):
return int(n, 16);
if __name__ == '__main__':
n = "1A";
print(HexToDec(n));
# This code is contributed by 29AjayKumarC#
// C# program to convert hexadecimal to decimal
using System;
public class GFG {
public static int HexToDec(String n)
{
return Convert.ToInt32(n, 16);
}
public static void Main(String[] args)
{
String n = "1A";
Console.WriteLine(HexToDec(n));
}
}
// This code is contributed by Amit KatiyarJavascript
输出
26使用预定义函数
Java
// Java program to convert hexadecimal to decimal
import java.io.*;
class GFG {
public static int HexToDec(String n)
{
return Integer.parseInt(n, 16);
}
public static void main(String[] args)
{
String n = "1A";
System.out.println(HexToDec(n));
}
}
Python3
# Python program to convert hexadecimal to decimal
def HexToDec(n):
return int(n, 16);
if __name__ == '__main__':
n = "1A";
print(HexToDec(n));
# This code is contributed by 29AjayKumar
C＃
// C# program to convert hexadecimal to decimal
using System;
public class GFG {
public static int HexToDec(String n)
{
return Convert.ToInt32(n, 16);
}
public static void Main(String[] args)
{
String n = "1A";
Console.WriteLine(HexToDec(n));
}
}
// This code is contributed by Amit Katiyar
Java脚本
输出
26