Why does this Java word scrambler keep returning an error?

Question

The error this word scrambler program gives back in the UNIX terminal after compiling and running as 'java' is

"Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0"

This is even after researching how to use "FileInputStream(args[0]))" and after constant debugging in 'jbd'

What this program is supposed to do is take a random word from a text file and then scramble it.

The text file "list.txt" reads exactly like this:

5
Apple
Pie
Horse
Computer
Tree

Here's the code:

import java.util.*;
import java.io.*;

class AnagramGenerator {
    public static void main(String[] args) throws FileNotFoundException {
        Random rand = new Random(1234);
        Scanner in = new Scanner(new FileInputStream(args[0]));

        int size = in.nextInt();
        int selection = rand.nextInt(size);
        int i = 0;
        while (i < selection) {
            in.next();
            i++;
        }
        String word = in.next();

        StringBuffer scrambled = scramble(word, rand);
        System.out.println(scrambled);
    }

        while(sbuf.length() > 0) {
            int next = rand.nextInt(sbuf.length());
            result.append(sbuf.charAt(next));
            sbuf.deleteCharAt(next);
        }
        return result;
    }
}

Thank you in advance.

[EDIT]: Coincidentally, I looked at the above link showing how to prevent such an error. The difference between this post and the other one is that this one scans directly from a text file (the first item is the number of words in the file) while the other one uses an array within the JAVA file. Sorry for this confusion.

What do you think `args[0]` should evaluate to? Why do you think so? — Savior, Apr 18 '16 at 18:56
Show us the command line you enter to run the program from the console. — Maljam, Apr 18 '16 at 18:57
There is no args[0]. (And if you are a Ghostbusters aficionado:) "There is only Zool" — ControlAltDel, Apr 18 '16 at 18:57
I enter "javac scrambler.java" and then it gives the error when I say "java scrambler" — J. Doe, Apr 18 '16 at 19:01
I thought that args[0] would command to scan the document at the first number in the array. What would be an alternative then? — J. Doe, Apr 18 '16 at 19:08
You probably need to read [this](https://docs.oracle.com/javase/tutorial/essential/environment/cmdLineArgs.html) to understand how to pass arguments to a java program. — Savior, Apr 18 '16 at 19:12
Oops, I meant text file instead of "document" or array. I'm trying to say I thought the program would read from the file, look at the first item 0 ("5"), and then interpret it as assigned to variable "i." — J. Doe, Apr 18 '16 at 19:14
How is your Java program related to that file in any way? Why should it know how to locate it? Does your file have a name? Are you passing that name to your java program in any way? — Savior, Apr 18 '16 at 19:19
My file's name is "list.txt." I think it's supposed to scan via "FileInputStream" — J. Doe, Apr 18 '16 at 19:20
You're running `java scrambler`. How is that program supposed to guess at something called `list.txt`? — Savior, Apr 18 '16 at 19:21
Oh, so in the terminal emulator I just mention the text file along with the Java file? How do I do that? — J. Doe, Apr 18 '16 at 19:23
`java scrambler `. Please read the official tutorial I linked to earlier. — Savior, Apr 18 '16 at 19:24
Read it already and the other link. Program works now. Thanks! — J. Doe, Apr 18 '16 at 19:28

Why does this Java word scrambler keep returning an error?

0 Answers0