Results 1 to 8 of 8
  1. #1
    mkarthik90 is offline Member
    Join Date
    Feb 2012
    Posts
    62
    Rep Power
    0

    Default problems with equals method.

    When i use the following code, the equals mehod return true if i use numbers , if i use a string as given in the code the method always returns false what could be the reason. The store.txt file contains the following lines as given. If i give the equal string as 1000 the match is produced and if i give as kp or kkn the output always states no match .


    store.txt
    kp
    1000
    kkn
    500

    Java Code:
    import java.io.*;
    class home 
    {
     public static void main(String args[])
      {
      try{
      // Open the file that is the first 
      // command line parameter
      FileInputStream fstream = new FileInputStream("store.txt");
      // Get the object of DataInputStream
      DataInputStream in = new DataInputStream(fstream);
      BufferedReader br = new BufferedReader(new InputStreamReader(in));
      String strLine;
    int value=0;
      //Read File Line By Line
      while ((strLine = br.readLine()) != null)  
      {
      // Print the content on the console
    	  
      System.out.println (strLine);
      	if(strLine.equals("kp"))
      	{
      		System.out.println("Match found");
      		 		
      		value = Integer.parseInt(strLine);
      		value=value+100;
      		System.out.println(value);
      	}
      	else
      		System.out.println("No match");
      }
      //Close the input stream
      in.close();
        }
      catch (Exception e){//Catch exception if any
      System.err.println("Error: " + e.getMessage());
      }
    
      
      
      }
    }
    Plz help me out
    Last edited by JosAH; 04-28-2012 at 10:14 AM.

  2. #2
    k1ng is offline Member
    Join Date
    Apr 2012
    Posts
    59
    Rep Power
    0

    Default Re: problems with equals method.

    Try using

    Java Code:
    if (r.compareToIgnoreCase("kp")==0)
    also if you're reading from a file I recommend making sure there's no rubbish around it by doing

    Java Code:
    if (r.trim().compareToIgnoreCase("kp")==0)

  3. #3
    JosAH's Avatar
    JosAH is offline Moderator
    Join Date
    Sep 2008
    Location
    Voorschoten, the Netherlands
    Posts
    13,337
    Blog Entries
    7
    Rep Power
    20

    Default Re: problems with equals method.

    If your String variable strLine equals "kp" it definitely doesn't represent an int value.

    kind regards,

    Jos
    cenosillicaphobia: the fear for an empty beer glass

  4. #4
    k1ng is offline Member
    Join Date
    Apr 2012
    Posts
    59
    Rep Power
    0

    Default Re: problems with equals method.

    This is true. I hadn't noticed you're looking for a string then trying to convert it to an int but it should spurt out "Match Found" before crashing :P

  5. #5
    mkarthik90 is offline Member
    Join Date
    Feb 2012
    Posts
    62
    Rep Power
    0

    Default Re: problems with equals method.

    Can someone clearly explain whats the problem with that if statement given in my code. ?

  6. #6
    Fubarable's Avatar
    Fubarable is offline Moderator
    Join Date
    Jun 2008
    Posts
    19,316
    Blog Entries
    1
    Rep Power
    26

    Default Re: problems with equals method.

    What I read your code as trying to do is:

    "If String is "kp" try to parse the String as an int."

    As Jos points out, this doesn't make sense -- how can one parse "kp" as an int?

  7. #7
    mkarthik90 is offline Member
    Join Date
    Feb 2012
    Posts
    62
    Rep Power
    0

    Default Re: problems with equals method.

    Ah! i dint paste the code on the line 24.
    Leave the lines 24 25 26 27 and execute the code still the same problem occurs man. !

  8. #8
    Fubarable's Avatar
    Fubarable is offline Moderator
    Join Date
    Jun 2008
    Posts
    19,316
    Blog Entries
    1
    Rep Power
    26

    Default Re: problems with equals method.

    Quote Originally Posted by mkarthik90 View Post
    Ah! i dint paste the code on the line 24.
    Leave the lines 24 25 26 27 and execute the code still the same problem occurs man. !
    Please paste the current code you're testing. Let's remove all doubt, OK?

Similar Threads

  1. What is the use of equals () method?
    By srinivasmallabathula in forum Advanced Java
    Replies: 3
    Last Post: 08-04-2011, 05:57 PM
  2. equals method :::::HELP:::::
    By alihht in forum New To Java
    Replies: 5
    Last Post: 03-09-2010, 07:19 AM
  3. ArrayLists compareTo method, equals method
    By random0munky in forum New To Java
    Replies: 2
    Last Post: 10-26-2009, 07:20 PM
  4. equals method
    By mani_miit in forum Advanced Java
    Replies: 7
    Last Post: 09-09-2009, 10:26 PM
  5. equals method
    By timkd127 in forum New To Java
    Replies: 2
    Last Post: 01-24-2009, 06:52 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •