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用16个符号{0, 1, 2, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F}来表示所有的数字。这里，(A, B, C, D, E, F)代表(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的数字并保留一个变量 dec_value。在从十六进制数中提取数字时，将数字乘以适当的基数(16 的幂)并将其添加到变量 dec_value。最后，变量 dec_value 将存储所需的十进制数。
例如：如果十六进制数是 1A。
dec_value = 1*(16^1) + 10*(16^0) = 26
下图解释了如何将十六进制数 (1AB) 转换为等效的十进制值：
下面是上述想法的实现。
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));
}
}
蟒蛇3
# 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
Javascript
输出
26