System.out.println not printing array data

Question

I am still very new to Java and have been trying to get a morse code translator to work. I overcame the first problem with various errors, but now the program compiles but will not print the results of the translation. Any help would be appreciated.

import java.util.Scanner;

public class MorseCode
{
    public static void main(String[] args)
    {
        Scanner Input = new Scanner(System.in);

        System.out.println("To convert English to Morse Code, type M. To convert Morse Code to English, type E.");

        String cType = Input.nextLine();

        String type = cType.toLowerCase();

        if(type == "m")
        {
            String eng;
            System.out.println("Please enter the English text to be translated.");
            eng = Input.nextLine();
            EToM(eng);
        }
        else
        {
            String morse;
            System.out.println("Please enter the Morse code text to be translated, with multiple words seperated by a |.");
            morse = Input.nextLine();
            MToE(morse);
        }
    }
    public static void EToM(String eng)
    {
        String EToMList[] = {".-", "-...", "-.-.", "-..", ".", "..-.", "--.", "....", "..", ".--", "-.-", ".-..", "--", "-.", "---", ".--.", "--.-", ".-.", "...", "-", "..-", "...-", ".--", "-..-", "-.--", "--..", ".----", "..---", "...--", "....-", ".....", "-....", "--...", "----.", "-----", "|"};

        String alphabet = "abcdefghijklmnopqrstuvwxyz123456789 ";
        String translation[] = new String[eng.length()];

        for(int x = 0; x < eng.length(); x++)
        {
            for(int y = 0; y < alphabet.length(); y++)
            {
                if(eng.charAt(x) == alphabet.charAt(y))
                {
                    translation[x] = EToMList[y];
                    System.out.println("test");
                }
            }
        }

        System.out.println("Your translated message is:");

        for(int z = 0; z < eng.length(); z++)
        {
            System.out.println(translation[z]); 
        }
    }

    public static void MToE(String morse)
    {

    }
}

try printing out something after you print out the contents of your array, and see how many iterations of your loop are running — Sam I am says Reinstate Monica, Aug 16 '13 at 15:19
Although your method is grossly inefficient in terms of coding, it compiles and runs fine ([demo link](http://ideone.com/UGDpGB)). — Sergey Kalinichenko, Aug 16 '13 at 15:23

score 3 · Answer 1 · edited May 23 '17 at 12:11

3

Your problem is

if(type == "m")

use

if("m".equals(type))

Your if-else will go to else because you are comparing String references and not String values. The else calls the MToE method which is empty. Read this: How Do I compare Strings in Java

edited May 23 '17 at 12:11

Community

1
1

answered Aug 16 '13 at 15:20

Sotirios Delimanolis

274,122
60
696
724

It looks to me like everything that the OP expects to happen before the printing of the translation is happening. If `type=="m"` was the issue, than it would never even print the `"test"` lines that the OP has – Sam I am says Reinstate Monica Aug 16 '13 at 15:22
@SamIam I haven't seen OP state that `test` was printed. – Sotirios Delimanolis Aug 16 '13 at 15:23
Why would the OP tell you that the problem was with the `results` if there's evidence of failure before `results`? – Sam I am says Reinstate Monica Aug 16 '13 at 15:25
@SamIam Because OP is _still very new to Java_. OP mus think there are results, but there actually aren't. – Sotirios Delimanolis Aug 16 '13 at 15:28
That's why i didn't actually down-vote; it's foolish to assume that the OP didn't miss any obvious symptoms, but I'm not up-voting either, at least not until the OP verifies that it is the issue. – Sam I am says Reinstate Monica Aug 16 '13 at 15:44
@SamIam OP has provided an SSCE, you can try it. – Sotirios Delimanolis Aug 16 '13 at 15:46

score 0 · Answer 2 · answered Aug 16 '13 at 15:24

When checking strings for equality in Java, always use the equals method on the String class. Changing the following:

if(type == "m")

to

if(type.equals("m"))

makes the English to Morse code translation output.

I made this modification and ran it successfully just now.

score 0 · Answer 3 · answered Aug 16 '13 at 15:25

0

use This

  if(type.equalsIgnoreCase("m")
  {

  }

answered Aug 16 '13 at 15:25

muthukumar

2,233
3
23
30

score -1 · Answer 4 · answered Aug 16 '13 at 15:25

You can use the deepToString method from Java to print out your array.

Documentation Link: http://docs.oracle.com/javase/1.5.0/docs/api/java/util/Arrays.html#deepToString(java.lang.Object[])

Here is a code sample:

System.out.println("Your translated message is:" + java.util.Arrays.deepToString(translation));

System.out.println not printing array data

4 Answers4