# Java: Convert a octal number to a hexadecimal number

## Java Basic: Exercise-27 with Solution

Write a Java program to convert a octal number to a hexadecimal number.

Octal number: The octal numeral system is the base-8 number system, and uses the digits 0 to 7.

Hexadecimal number: This is a positional numeral system with a radix, or base, of 16. Hexadecimal uses sixteen distinct symbols, most often the symbols 0-9 to represent values zero to nine, and A, B, C, D, E, F (or alternatively a, b, c, d, e, f) to represent values ten to fifteen.

*Test Data:*

Input any octal number: 100

**Pictorial Presentation: Octal to Hexadecimal number**

**Sample Solution**:

**Java Code:**

```
public class Exercise27 {
public static void main(String args[]) {
// Declare variables to store octal number and its decimal and hexadecimal equivalents
String octal_num, hex_num;
int decnum;
// Create a Scanner object to read input from the user
Scanner in = new Scanner(System.in);
// Prompt the user to input an octal number
System.out.print("Input an octal number : ");
octal_num = in.nextLine();
// Convert the octal number to its decimal equivalent using parseInt
decnum = Integer.parseInt(octal_num, 8);
// Convert the decimal number to its hexadecimal equivalent
hex_num = Integer.toHexString(decnum);
// Display the equivalent hexadecimal number
System.out.print("Equivalent hexadecimal number: " + hex_num + "\n");
}
}
```

**Explanation:**

In the exercise above -

- First, it takes an octal number as input from the user using the "Scanner" class and stores it as a string in the variable 'octal_num'.
- It uses the "Integer.parseInt()" method to convert the 'octal_num' string to an integer 'decnum', specifying base 8 (octal) as the input radix.
- It then uses the "Integer.toHexString()" method to convert the 'decnum' to its hexadecimal representation and stores it in the 'hex_num' string.
- Finally, it prints the hexadecimal representation of the original octal number stored in the 'hex_num' variable.

Sample Output:

Input a octal number : 100 Equivalent hexadecimal number: 40

**Flowchart: **

**Java Code Editor:**

**Previous:** Write a Java program to convert a octal number to a binary number.

**Next:** Write a Java program to convert a hexadecimal to a decimal number.

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