﻿ Java exercises: Convert a decimal number to octal number - w3resource # Java Exercises: Convert a decimal number to octal number

## Java Basic: Exercise-21 with Solution

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

Decimal number: The decimal numeral system is the standard system for denoting integer and non-integer numbers. It is also called base-ten positional numeral system.

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

Pictorial Presentation: Decimal to Octal number Sample Solution:

Java Code:

``````import java.util.Scanner;
public class Exercise21 {
public static void main(String args[])
{
int dec_num, rem, quot, i=1, j;
int oct_num[] = new int;
Scanner scan = new Scanner(System.in);

System.out.print("Input a Decimal Number: ");
dec_num = scan.nextInt();

quot = dec_num;

while(quot != 0)
{
oct_num[i++] = quot%8;
quot = quot/8;
}

System.out.print("Octal number is: ");
for(j=i-1; j>0; j--)
{
System.out.print(oct_num[j]);
}
System.out.print("\n");
}
}
```
```

Sample Output:

```Input a Decimal Number: 15
Octal number is: 17
```

Flowchart: Java Code Editor:

What is the difficulty level of this exercise?

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## Java: Tips of the Day

Try and catch:

Java is excellent at catching errors, but it can only recover gracefully if you tell it what to do. The cascading hierarchy of attempting to perform an action in Java starts with try, falls back to catch, and ends with finally. Should the try clause fail, then catch is invoked, and in the end, there's always finally to perform some sensible action regardless of the results. Here's an example:

```try {
cmd = parser.parse(opt, args);

if(cmd.hasOption("help")) {
HelpFormatter helper = new HelpFormatter();
helper.printHelp("Hello ", opt);
System.exit(0);
}
else {
if(cmd.hasOption("shell") || cmd.hasOption("s")) {
String target = cmd.getOptionValue("tgt");
} // else
} // fi
} catch (ParseException err) {
System.out.println(err);
System.exit(1);
} //catch
finally {
new Hello().helloWorld(opt);
} //finally
} //try
```

It's a robust system that attempts to avoid irrecoverable errors or, at least, to provide you with the option to give useful feedback to the user. Use it often, and your users will thank you!

Ref: https://red.ht/3EZc9OC