Program Help

[Adam Stever]

I am posting a program that needs some obvious attention, My goal here is to prompt the user wether they would like to encrypt or decrypt their file and obviously just incement by 1, Please help.

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

public class FileFun{

	public static void main (String[]args){
	
		PrintWriter fileOut; // print out to a file
		Scanner fileIn; // to read a file in
		Scanner console = new Scanner (System.in); 
		String fileName = ""; // variable that allow us to store the file name
		String line = ""; // enable us to read one line at a time
		int function = 0;// 1 to encrypt 2 to decrypt
		char ch[]; // temp storing for each character
		ArrayList<String> name = new ArrayList<String>();
           // stores multiple characters and assists in ecrypting and decrypting
		
		try{
		// get file name and either encrypt or decrypt
		System.out.println("Please enter a file name");
		fileName = console.nextLine();
		System.out.println("Would you like to Encyrpt or Decrypt your file? \n Press 1 to Encrypt or 2 to Decrypt");
		function = console.nextInt();
		fileIn = new Scanner (new FileReader (fileName));
		fileOut = new PrintWriter("Java Encrypt/Decrypt");
		
		if (function == 1)
		
			while (fileIn.hasNextLine())
			{
				line = fileIn.nextLine();
			
				for (int i=0; i<fileName.length(); i++)
				{
					if (fileName [i] = ch);
				
					{
					System.out.println(fileName [i+1]);
					}
					
					else (fileName!= ch);
					{
					System.out.println(fileName [i-1]);
					}
				}// end for
				
			}// end while
		
			fileOut.close();
			
		}// end try
		catch (FileNotFoundException e)
		{
		System.out.println("Error:" + e.getMessage());
		}
	
	
	}// end main

}// end class

[John Jai]

Please TellTheDetails. What are the errors you are facing?

One obvious error is you have declared fileName as a String variable, but you try to use it as an array.

[Michael Krimgen]

Hi,

I am not sure what exactly your program is supposed to do, so it would be good to have an explanation.

However, the following part of your code looks rather odd to me:

                    if (fileName [i] = ch);   
                   
                    {   
                    System.out.println(fileName [i+1]);   
                    }   
                       
                    else (fileName!= ch);   
                    {   
                    System.out.println(fileName [i-1]);   
                    }   

I have some doubts that it does what you intend it should do.

1) You have semicolons after the if and else, which in fact represent an empty statement. The following blocks in curly brackets will always be executed.
2) if (fileName [i] = ch) is an assignment, not a condition

[Campbell Ritchie]

Well done picking up the extra semicolons. I think that block won’t even complete since the else is separated from its if by the semicolons.

[Campbell Ritchie]

This thread looks to me like a duplicate of the last question here, so I shall close it.