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Thread: could anyone tell me why am I getting this error?

  1. #1
    Member
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    Default could anyone tell me why am I getting this error?

    Exception in thread "main" java.lang.NumberFormatException: For input string: "datafile.txt"
    	at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
    	at java.lang.Integer.parseInt(Integer.java:492)
    	at java.lang.Integer.parseInt(Integer.java:527)
    	at postfixstack.Main.main(Main.java:27)
    Java Result: 1

    the file contains

    1 + 2 - 3

    I'm creating two stacks 1: operands, and 2: operators, and then displaying it

    line 27 in Main contains "oprand.push(Integer.parseInt(next));"


    package postfixstack;
     
    import java.util.*;
     
    public class Main {
     
        public static void main(String[] args)
        {
            Stack<String> optor = new Stack();
            Stack<Integer> oprand = new Stack();
     
            Scanner in = new Scanner("datafile.txt");
     
            while(in.hasNext())
            {
                String next = in.next();
                if(optor.isOperator(next))
                    optor.push(next);
                else
                {
                    oprand.push(Integer.parseInt(next));
                }
     
            }
     
            System.out.println("Operators");
            optor.display();
     
            System.out.println("Operands");
            oprand.display();
        }
     
    }
    Last edited by mia_tech; June 25th, 2012 at 06:47 PM.


  2. #2
    Junior Member
    Join Date
    Jun 2012
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    Default Re: could anyone tell me why am I getting this error?

    Scanner in = new Scanner("datafile.txt") //wrong way

    //RIGHT WAY
    File file = new File("datafile.txt");
    Scanner in = new Scanner(file);

    I hope that helps if the rest of your code is right

  3. The Following User Says Thank You to kindk12 For This Useful Post:

    mia_tech (June 26th, 2012)