A generic morse code encode/decode exercise.

morse encode and decode

var charCodes= {
	"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": "_ _ _ _ _"
};
var encodeMorse = function (string) {
	var chars = string.toLowerCase().split("");
	var value = "";

	for (var a = 0; a < chars.length; a++) {
		if (charCodes[chars[a]]) {
			value += charCodes[chars[a]] + "  ";
		}
	}

    return value;
};
var decodeMorse = function (string) {
	var morseChars = string.split("  ");
	var value = "";

	for (var a = 0; a < morseChars.length; a++) {
		if (morseChars[a].length && morseChars[a] !== " ") {
			value += getKeyByValue(morseChars[a], charCodes);
		}
	}

    return value;
};
var getKeyByValue = function (keyValue, object) {
	for (var prop in object) {
		if (object.hasOwnProperty(prop)) {
			if (object[prop] === keyValue) {
				return prop;
			}
		}
	}
};
var count = function (string, char) {
	var re = new RegExp(char,"g");
	return string.match(re).length
};
var countDashes = function (string) {
	return count(string, "_");
};
var countDots = function (string) {
	return count(string, "\\.");
};
var countDashesAndDots = function (string) {
	var numOfDashes = countDashes(string);
	var numOfDots = countDots(string);
	return ("There are " + numOfDashes + " dashes and there are " + numOfDots + " dots.");
};
var word = "Testing!";
var morse = encodeMorse(word);
var text = decodeMorse(morse);
console.log("Original word: " + word);
console.log("Encoded word: " + morse);
console.log(countDashesAndDots(morse));
console.log("Decoded morse: " + text);

Just a generic exercise - want to revisit with map and filter instead of loops, and revisit performance.