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# Java program to convert hexadecimal byte to decimal

Given a byte value in the hexadecimal format, we have to convert hexadecimal byte to decimal.
Submitted by Nidhi, on March 02, 2022

## Problem statement

In this program, we will convert the hexadecimal byte into a decimal number and print the result.

## Java program to convert hexadecimal byte to decimal

The source code to convert hexadecimal byte to decimal is given below. The given program is compiled and executed successfully.

```// Java program to convert hexadecimal Byte
// to an integer

public class Main {
static int getNum(char ch) {
int num = 0;

if (ch >= '0' && ch <= '9') {
num = ch - 0x30;
} else {
switch (ch) {
case 'A':
case 'a':
num = 10;
break;

case 'B':
case 'b':
num = 11;
break;

case 'C':
case 'c':
num = 12;
break;

case 'D':
case 'd':
num = 13;
break;

case 'E':
case 'e':
num = 14;
break;

case 'F':
case 'f':
num = 15;
break;

default:
num = 0;
}
}
return num;
}

static int hex2int(String hex) {
int x = 0;

x = (getNum(hex.charAt(0))) * 16 + (getNum(hex.charAt(1)));

return x;
}

public static void main(String[] args) {
String hexValue = "7F";
int intValue = 0;

intValue = hex2int(hexValue);

System.out.printf("Value is: %d\n", intValue);
}
}
```

### Output

```Value is: 127
```

## Explanation

In the above program, we imported the "java.util.Scanner" package to read input from the user. And, created a public class Main. It contains three static methods getNum(), hex2int(), and main().

The getNum() method is used to get a decimal digit from a hexadecimal digit and return the result to the calling method.

The hex2int() method is used to return a decimal number from the hexadecimal number and return the result to the calling method.

The main() method is an entry point for the program. Here, we created a string variable hexValue initialized with "7F". Then we converted the hex value into decimal using the hex2int() method and printed the result.