CODEWITHSUNDEEP
java
VanDal
VanDal

Reputation: 25

Beginner - Java 2D Array

I've created the following:

import java.util.*;

public class morse5 {

public static void main(String [] args)
{     

  //Declare Variables
  String [][] myIndexAlphaMorse = {{"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", "--.."}, {"1", ".----"}, {"2", "..---"}, {"3", "...--"}, {"4", "....-"}, {"5", "....."}, {"6", "-...."}, {"7", "--..."}, {"8", "---.."}, {"9", "----."}, {"0", "-----"}, {" ", "|"}}; 


  //Test
  System.out.println(Arrays.deepToString(myIndexAlphaMorse));
  System.out.println(myIndexAlphaMorse[8][0]);


}

What I would like to know is how to get the value of the corresponding position based on user input. I'm learning, so I just want the piece on how to get, as an example, .- back when "a" is entered.

Upvotes: 1

Views: 68

Answers (5)

Wojtek
Wojtek

Reputation: 1308

First of all you have to read the letter as the String object. Then you can just iterate through your array and when we find what we are looking for - just print it and break the loop:

Scanner scanner = new Scanner(new InputStreamReader(System.in));
String letter = scanner.next();
for (int i=0; i<myIndexAlphaMorse.length; i++)
    if (myIndexAlphaMorse[i][0].equals(letter)){
        System.out.println(myIndexAlphaMorse[i][1]);
        break;
    }

Upvotes: 1

C0L.PAN1C
C0L.PAN1C

Reputation: 12233

You can also use Hash tables, since they've already given sample above of HashMap/Map:

Hashtable<String, String> table = new Hashtable<String, String>();
table.put("a", ".-");
table.put("b", "-...");

It is also synchronized and thread safe unlike HashMaps, albeit is a smidgen slower for bigger data sets.

Upvotes: 1

ArcticLord
ArcticLord

Reputation: 4039

Simply iterate over you array and compare the 0th element at each position with the character you are looking for.

String input = "v";
String result= "";
for(int i = 0; i < myIndexAlphaMorse.length; i++){
    if(myIndexAlphaMorse[i][0].equals(input)){
        result = myIndexAlphaMorse[i][1];
        break;
   }
}
System.out.println("morse for " + input + " = " + result);

But as the other answer says you should use a map that whould fit perfect for this task.

Upvotes: 3

deviantxdes
deviantxdes

Reputation: 479

Or a map of string arrays

Map<String, String[]> myIndexAlphaMap = new HashMap<String, String[]>();
myIndexAlphaMap.put("a", new String {".","-"});
myIndexAlphaMap.put("b", new String {"-",".","."});

// given user input of "a" you can access via
myIndexAlphaMap.get("a")[0];

Upvotes: 1

Tim Biegeleisen
Tim Biegeleisen

Reputation: 520908

You should consider using a Map instead of a two dimensional array for this problem:

Map<String, String> myIndexAlphaMap = new HashMap<>();
myIndexAlphaMap.put("a", ".-");
myIndexAlphaMap.put("b", "-...");
// etc.

// given user input of "a" you can access via
myIndexAlphaMap.get("a");

Upvotes: 2

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