Help with english to morse code program, I have no idea what I'm doing

[Jay Watson]

  import java.io.*;

public class MorseCode {

public static void main(String[] args){
    BufferedReader BR = new BufferedReader(new InputStreamReader(System.in)); 
   
    
   String[] morse = {".- ","-... ","-.-. ","-.. ",". ","..-. ","--. ",".... ",".. ",
   ".--- ","-.- ",".-.. ","-- ","-. ","--- ",".--. ","--.- ",".-. ","... ","- ","..- ",
   "...- ",".-- ","-..- ","-.-- ","--.. "};
   String[] letter = {"A","B","C ","D","E","F","G","H","I",
   "J","K","L","M","N ","O","P","Q","R","S","T","U",
   "V","W","X","Y ","Z"}; 
   
   
   int y=0;
    String val="";
   try  { 
      
       System.out.println("Input: ");  
       val = BR.readLine();  
       int x =Integer.parseInt(val);
       
      }catch(Exception e){       
                System.out.println("error");       
           }    
   
   
    switch(y){
            
             case 1:System.out.println(morse[0]);       
                      break;       
             case 2:System.out.println(morse[1]);      
                      break;       
             case 3:System.out.println(morse[2]);       
                      break;       
             case 4:System.out.println(morse[3]);      
                      break;       
             case 5:System.out.println(morse[4]);      
                      break;       
             case 6:System.out.println(morse[5]);      
                      break;       
             case 7:System.out.println(morse[6]);       
                      break;       
             case 8:System.out.println(morse[7]);       
                      break;       
             case 9:System.out.println(morse[8]);    
                      break;       
             case 10:System.out.println(morse[9]);       
                      break;       
             case 11:System.out.println(morse[10]);      
                      break;       
             case 12:System.out.println(morse[11]);      
                      break;       
             case 13:System.out.println(morse[12]);       
                      break;       
             case 14:System.out.println(morse[13]);     
                      break;       
             case 15:System.out.println(morse[14]);       
                      break;       
             case 16:System.out.println(morse[15]);      
                      break;       
             case 17:System.out.println(morse[16]);      
                      break;       
             case 18:System.out.println(morse[17]);       
                      break;       
             case 19:System.out.println(morse[18]);     
                      break;       
             case 20:System.out.println(morse[19]);       
                      break;       
             case 21:System.out.println(morse[20]);      
                      break;       
             case 22:System.out.println(morse[21]);      
                      break;       
             case 23:System.out.println(morse[22]);       
                      break;       
             case 24:System.out.println(morse[23]);       
                      break;       
             case 25:System.out.println(morse[24]);       
                      break;       
             case 26:System.out.println(morse[25]);       
                      break;       
            }
    
   
  
           
    
    
    
    
    
    
    
    
    
}

}  

Here is the output

  compile-single:
run-single:
Input: 
QUICK BROWN FOX
error
BUILD SUCCESSFUL (total time: 50 seconds)

  

I know there are tons of errors, I need your advice. Please, this is due in 5 hours.

Thanks

[Sagar Rohankar]

Please, this is due in 5 hours.

Please, DoYourOwnHomework

[edited: I found 'y' ]

[Joanne Neal]

In your catch block, add tghe line
e.printStackTrace();
This will give you a lot more information about what the problem is.

Also, you are assigning the return value from parseInt to 'x', but your switch statement is checking the value of 'y' which will always be 0.

[Jay Watson]

The word error is from the catch. I think the reason the word error appears bec. I inputted a character instead of an Integer.
I'm not asking you to do my homework I just need someone to help me.

[Jay Watson]

I tried assigning x to the switch statement but it just gives me error. Is there any way to use br.readline w/o the try and catch?

[Ulf Dittmer]

The word error is from the catch. I think the reason the word error appears ...

If you print out the stack trace like Joanne suggests you'll know for sure. No sense in wasting time if you're under a deadline.

And make sure to read your private messages (to be found under the "My Private Messages" link at the top of the page).

[Joanne Neal]

Shen anigans wrote:I tried assigning x to the switch statement but it just gives me error. Is there any way to use br.readline w/o the try and catch?

You don't need x. Assign the value returned from parseInt to 'y'.

One other thing. You can replace your whole switch statement with one line of code. Notice that when 'y' is 1, you print out the value of morse[0], when 'y' is 2, you print out the value of morse[1], etc. Can you see a pattern ?

[Sagar Rohankar]

Convert the string 'val' into the chary:
http://java.sun.com/javase/6/docs/api/java/lang/String.html#toCharArray()

PatienceIsAVirtue and welcome to JR

[salvin francis]

System.out.println("error");

would be better as:

e.printStackTrace();

to be honest, your program does not make sense to me,

instead of doing:

val = BR.readLine();    
int x =Integer.parseInt(val);  

if you want to get code running fast,
you can do something like

String val="F";

'BR' is not a good naming convention, you might want to change that.


The program would have been a lot more simpler if you had used ArrayList

code snippet:

int stringIndex = alphabetArray.indexOf(val);
if(stringIndex != -1)
{
    System.out.println("Morse: "+morseArray.get(stringIndex));
}

pardon me for any typos in the above code, i wrote it in a giffy.

if you are not allowed to use ArrayList, you can use an array of strings and run a loop to get the index.

[Campbell Ritchie]

Please avoid abbreviations like "bec".

Salvin Francis, there is a much better data structure than a List. What you are trying to do is to match a letter (eg S) to a pattern (eg "..."). A good place for a beginner to look would be to go through the different interfaces in this Java™ Tutorials section.

[salvin francis]

true, there are more optimized and better approaches.
I was trying to ease out his burden by removing the user entry part to bring him up to speed. I know the data structure you are referring to, but I wonder why you haven't mentioned it here.

[Campbell Ritchie]

I didn't name it because the assignment was homework.

[Jay Watson]

I got the program running.It works fine, But is there any other way other than switch statement?

   import java.io.*;

public class MorseCode {

public static void main(String[] args){
    BufferedReader BR = new BufferedReader(new InputStreamReader(System.in)); 
   
    
   String[] morse = {".- ","-... ","-.-. ","-.. ",". ","..-. ","--. ",".... ",".. ",
   ".--- ","-.- ",".-.. ","-- ","-. ","--- ",".--. ","--.- ",".-. ","... ","- ","..- ",
   "...- ",".-- ","-..- ","-.-- ","--.. "};
  
   
   

BufferedReader dataIn = new BufferedReader(new InputStreamReader(System.in));

String sentence = "";
System.out.println("Enter a sentence");
try{
sentence = dataIn.readLine();
}catch(Exception e){
System.out.println("Invalid Input");
}

for(int x = 0; x<sentence.length(); x++){

char ch = sentence.charAt(x);


 


switch(ch){
case 'a':
case 'A':
System.out.println(morse[0]); break;

case 'b':
case 'B':
System.out.print(morse[1]); break;

case 'c':
case 'C':
System.out.print(morse[2]); break;

case 'd':
case 'D':
System.out.print(morse[3]); break;

case 'e':
case 'E':
System.out.print(morse[4]); break;

case 'f':
case 'F':
System.out.print(morse[5]); break;

case 'g':
case 'G':
System.out.print(morse[6]); break;

case 'h':
case 'H':
System.out.print(morse[7]); break;

case 'i':
case 'I':
System.out.print(morse[8]); break;

case 'j':
case 'J':
System.out.print(morse[9]); break;

case 'k':
case 'K':
System.out.print(morse[10]); break;

case 'l':
case 'L':
System.out.print(morse[11]); break;

case 'm':
case 'M':
System.out.print(morse[12]); break;

case 'n':
case 'N':
System.out.print(morse[13]); break;

case 'o':
case 'O':
System.out.print(morse[14]); break;

case 'p':
case 'P':
System.out.print(morse[15]); break;

case 'q':
case 'Q':
System.out.print(morse[16]); break;

case 'r':
case 'R':
System.out.print(morse[17]); break;

case 's':
case 'S':
System.out.print(morse[18]); break;

case 't':
case 'T':
System.out.print(morse[19]); break;

case 'u':
case 'U':
System.out.print(morse[20]); break;

case 'v':
case 'V':
System.out.print(morse[21]); break;

case 'w':
case 'W':
System.out.print(morse[22]); break;

case 'x':
case 'X':
System.out.print(morse[23]); break;

case 'y':
case 'Y':
System.out.print(morse[24]); break;

case 'z':
case 'Z':
System.out.print(morse[25]); break;
}
}   
System.out.println(".");

}

} 

[fred rosenberger]

Jay Watson wrote:I got the program running.It works fine, But is there any other way other than switch statement?

yes.

First, you may want to 'normalize' your data. if you convert the input to all uppercase, for example, you don't need to account for both 'D' and 'd' as input.

second, note that char variables are really just integer values. Joanne gave you a BIG hint above:

One other thing. You can replace your whole switch statement with one line of code. Notice that when 'y' is 1, you print out the value of morse[0], when 'y' is 2, you print out the value of morse[1], etc. Can you see a pattern ?

[Jay Watson]

  import java.io.*;

public class MorseCode {

public static void main(String[] args){
    BufferedReader dataIn = new BufferedReader(new InputStreamReader(System.in)); 
   
    
   String[] morse = {".- ","-... ","-.-. ","-.. ",". ","..-. ","--. ",".... ",".. ",
   ".--- ","-.- ",".-.. ","-- ","-. ","--- ",".--. ","--.- ",".-. ","... ","- ","..- ",
   "...- ",".-- ","-..- ","-.-- ","--.. "};
  
    
   
String sentence = "";
System.out.println("Enter a sentence: ");
try{
sentence = dataIn.readLine();
}catch(Exception e){
System.out.println("Invalid Input");
}

        for(int i = 0;i < sentence.length();i++) {    
       [code] String m = morse[sentence.charAt(0) - 'A'];
        System.out.print(m);
        }



  

}
} 

Why is it not working?

   String m = morse[sentence.charAt(0) - 'A'];  

What is wrong with this line?

[Ulf Dittmer]

There may other problems, but instead of "sentence.charAt(0)" you should have "sentence.charAt(i)".

[Jay Watson]

Ulf Dittmer wrote:There may other problems, but instead of "sentence.charAt(0)" you should have "sentence.charAt(i)".

other problems like?

[Ulf Dittmer]

Don't know, I haven't run the code. Does it work?

[Jay Watson]

It runs. My problem is every time I input a space it gives me an error.

[Jay Watson]

Why won't it read space?

import java.io.*;

public class MorseCode {

public static void main(String[] args){
    BufferedReader dataIn = new BufferedReader(new InputStreamReader(System.in)); 
   
    
   String[] morse = {".- ","-... ","-.-. ","-.. ",". ","..-. ","--. ",".... ",".. ",
   ".--- ","-.- ",".-.. ","-- ","-. ","--- ",".--. ","--.- ",".-. ","... ","- ","..- ",
   "...- ",".-- ","-..- ","-.-- ","--.. "," "};
  
       String sentence = "";
       System.out.println("Enter a sentence: ");
      try{
          sentence = dataIn.readLine();
      }catch(Exception e){
          System.out.println("Invalid Input");
       }


  
          for (int i = 0; i < sentence.length(); i++) {
               char letter = Character.toUpperCase(sentence.charAt(i));
                  String word = morse[letter - 'A'];
                  System.out.print(word+".");
               }
         }

       }

Enter a sentence: 
G G
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: -33
        at MorseCode.main(MorseCode.java:25)
--. .
Java Result: 1
BUILD SUCCESSFUL (total time: 28 seconds)

[Karthick Dharani Vidhya]

It broke because all your code know is MORSE code for only A to Z.
Actually it will break for anything else apart from A-Z like numbers, special characters [@.!.$.%, etc]

If you need to convert only the Alphabets to MORSE code, then checkout

   Character.isLetter('a') 

that tells you if the char is a letter or not. If you need to convert the whole input string to Morse code, then you have to think of adding separate arrays for numbers and special characters and handle them

[Jesper de Jong]

Jay Watson wrote:Why won't it read space?

String word = morse[letter - 'A'];

To solve this, ask yourself what letter contains when the program encounters a space, and what the value of letter - 'A' is in that case (hint: the error message already says it). Think about how to handle space, or any other character outside of the alphabet letters.

[Campbell Ritchie]

Since Morse code only uses the 26 letters of the English alphabet, it will only use ASCII characters, so the numbers can be obtained from 'a' % 0x20. Then you can get at the array index but may require -1. Of course if you enter " " as the 0-th element in your array and use a 27-member array, you can put the space back; space is 0x20.
0x20 is what most people call 32.

I was actually thinking about a Map<Character, String> for storing the Morse code, yesterday.

[salvin francis]

you finally said it

[Campbell Ritchie]

salvin francis wrote:you finally said it

Only when there was no risk of it being used as cheating for the assignment. I am sure you had it worked out, didn't you

[salvin francis]

naa