Practice Exercise

Morse Code translator

Morse code is a system of encoding developed in the 1800s that allowed transmission of textual messages over signal systems that only supported on/off (1 and 0) notations.

Complete the program below as specified. Your program should be able to translate messages like -- --- .-. ... ./-.-. --- -.. . into MORSE CODE and vice versa. Use what you learned above about Objects, and also some of the built-in Objects we've studied, in particular RegExp and String.

Use the following limited set of morse code to use in this exercise. You could expand your program to handle more complex messages later if you want:

Letter	Morse
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	`--..`
space	`/`

NOTE: letters are separated by a single space (' ') within a word, and words are separated with a /. For example, the words MORSE CODE would translate to -- --- .-. ... ./-.-. --- -.. .

// Object to provide lookup of morse code (value) for a given letter (key).
let alpha = {
  // define the mapping here as a literal
};

// Object to provide lookup of letter (value) for a given morse code (key).
let morse = {};
// Hint: use the [] operator to specify these special key values rather than a literal.

// Return `true` if all characters are morse code.  Use a RegExp.
function isMorse(characters) {}

// Return `true` if all characters are part of the alphabet defined in `alpha`.  Use a RegExp.
// Bonus: can you rewrite it using `Object.keys()` and your `alpha` Object instead?
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/keys
function isAlpha(characters) {}

// Given an alphabet message, convert and return in morse code.  Use your morse and/or alpha object.
// Return undefined if text is not alpha.
function textToMorse(text) {}

// Given a morse code message, convert and return in text.  Use your morse and/or alpha object.
// Return undefined if morse is not proper code.
function morseToText(morse) {}

// Message class that takes a `message` (String), which can be either morse or alpha.
// Use your functions above to decide how to store a value for `any` on `this`
class Message {
  constructor(text) {}

  // Return the message as morse code, converting if necessary
  toMorse() {}

  // Return the message as alpha characters, converting if necessary
  toAlpha() {}
}

let msg1 = new Message(
  '--- -... .--- . -.-. - .../.. -./.--- .- ...- .- ... -.-. .-. .. .--. -/.- .-. ./...- . .-. -.--/.--. --- .-- . .-. ..-. ..- .-..'
);
console.log(msg1.toAlpha());
console.log(msg1.toMorse());

let msg2 = new Message('I am learning how to use Objects in JavaScript');
console.log(msg2.toMorse());
console.log(msg2.toAlpha());

You can download the code above as well as a possible solution.

Morse Code translator​

Morse Code translator