parseInt?

[aesoprock00]

Hey guys, so i'm working on an assignment for a class, and i'm having a little difficulty. so the assignment is a Finite State Machine, and what i need it to do is take input from a file via a bufferedReader, and input it into an array based on variable in the file being inputted.

my problem is, when i'm trying to input the values/variables, when i read them from the BufferedReader, they're coming in as Strings, right? and for the array i need them to be Int values. do i need to parseInt somewhere, and if so, where? i'll post the code i've got so far, but i keep coming up with an error, which i'll also post. Thank you very much to everyone looking and anyone helping. DevX forums have always been a great help and resource.

//Assignment 3


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

public class FSA{
	private String machineName;
	private int numStates;
	private String alphabet;
	private int[][] transitions;
	private String tape;
	private int start;
	private boolean[] acceptStates;

     	BufferedReader inp = null;
   	String fileName = null;
   	Scanner keyBD = new Scanner(System.in);

    public String FSM(String filename){
	      try{
			  System.out.print("File Name: ");
			  fileName = keyBD.nextLine();
		  inp = new BufferedReader(new FileReader(fileName));

	String machineName = inp.readLine();
	int numStates = inp.read();
	int start = inp.read();
	String alphabet = inp.readLine();

	int[][] transitions = new int[numStates][alphabet];

	inp.close();
	}
	catch(FileNotFoundException e){
			System.out.println("***File Not Found***");
		}
}
}

and the compile error i keep getting is:

C:\java\FSA.java:32: incompatible types
found   : java.lang.String
required: int
	int[][] transitions = new int[numStates][alphabet];
                                                              ^

Thank you all!

[nspils]

You've declared alphabet to be an object of class String. It cannot be used to dimension the size of your array. Perhaps you want to declare an int alphabetInt which is then given a value when you parse the string value using alphabetInt = Integer.getInteger( alphabet ).

Of course you could use that value directly in dimensioning your array.

Have you looked at using the Scanner class, rather than a buffered reader?

[aesoprock00]

while i would prefer to use the Scanner class, part of the assignment is specifically using the BufferedReader.

and i'll try the alphabetInt and parse that. thanks!

[aesoprock00]

well, when i change the code around and put that alphabetInt in it gives me a whole bunch of other errors.

C:\java\FSA.java:44: missing return statement
}
^
C:\java\FSA.java:28: unreported exception java.io.IOException; must be caught or declared to be thrown
	String machineName = inp.readLine();
                                         ^
C:\java\FSA.java:29: unreported exception java.io.IOException; must be caught or declared to be thrown
	line = inp.readLine();
                           ^
C:\java\FSA.java:31: unreported exception java.io.IOException; must be caught or declared to be thrown
	lineTwo = inp.readLine();
                              ^
C:\java\FSA.java:33: unreported exception java.io.IOException; must be caught or declared to be thrown
	String alphabet = inp.readLine();
                                      ^
C:\java\FSA.java:39: unreported exception java.io.IOException; must be caught or declared to be thrown
	inp.close();
                 ^
6 errors

Tool completed with exit code 1

[nspils]

Your FSM method is declared as returning an object of class String, but you are not returning an object.

The compiler is complaining about the BufferedReader object. Take a look at the manner in which you are defining it. Shouldn't it be in its own little try-catch block?

[srekcus]

You're code is kind of confusing but the code below compiles...

//Assignment 3

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

public class FSA {

	private String machineName;
	private int numStates;
	private String alphabet;
	private int[][] transitions;
	private String tape;
	private int start;
	private boolean[] acceptStates;

	BufferedReader inp = null;
	String fileName = null;
	Scanner keyBD = new Scanner(System.in);

    public String FSM(String filename) throws IOException {

		try{

			System.out.print("File Name: ");
			fileName = keyBD.nextLine();
			inp = new BufferedReader(new FileReader(fileName));

			machineName = inp.readLine();
			numStates = inp.read();
			start = inp.read();
			alphabet = inp.readLine();

			int[][] transitions = new int[numStates][Integer.parseInt(alphabet)];

			inp.close();

			return "whatever String you want";

		} catch(FileNotFoundException e){

			return "***File Not Found***";

		}

	}

}

All I really did was add Integer.parseInt() around your variable "alphabet" in the array declaration. After that the method needed to throw IOException, and it needed return statements since it returns a String. Also, you can remove the variable types inside of the FSM() method since you already cast them as global variables above.

[aesoprock00]

Thank you both very very much for the help!

[prolific]

hello
try declaring another variable like this
int b =Integer.parseInt(numberStates)

in the array declaration use b instead of numberStates
Cheerio