Code snippets for ThoughtWorks Team Hug presentation - comparing JavaScript and CoffeeScript (part 3)

10a-for-own-loop.js

var objectToString = function (obj) {
	var key, val, _results;
	_results = [];

	for (key in obj) {
		if (!obj.hasOwnProperty(key)) continue;
		val = obj[key];
		if (val !== null) _results.push(key + ":" + val);
	}
	return _results.join(",");
};

10b-for-own-loop.coffee

objectToString = (obj) ->
  	("#{key}:#{val}" for own key, val of obj when val isnt null).join(“,")

11a-constructor.js

var Region = function(states) {
	this.states = states;
};

Region.prototype.findStatesBeginningWith = function(letter) {
	var matchingStates = [];
       for (var i = 0;i < this.states.length; i++) {
		state = this.states[i];
		if (state.substr(0,1) === letter) {
			matchingStates.push(state)
		}
	}
	return matchingStates;
};

11b-constructor.coffee

class Region

  constructor: (@states) ->

  findStatesBeginningWith: (letter) ->
    state for state in @states when state.substr(0,1) is letter

12a-binding.js

var Clickable = function (baseElement) {
	var that = this;
	this.displayAlert = function() {
		alert("You just clicked me!");
	};
	$(baseElement).click(that.displayAlert);
};

12b-binding.coffee

class window.Clickable

  constructor: (@baseElement) ->
    $(@baseElement).click(@displayAlert)

  displayAlert: =>
    window.alert("You just clicked me!")

13a-pattern-matching-1.js

var london = {
  lat: 51.5171,
  lng: 0.1062
};

var lat = london.lat;
var lng = london.lng;

13b-pattern-matching-1.coffee

london =
  lat: 51.5171
  lng: 0.1062

{lat,lng} = london

14a-pattern-matching-2.js

function doSomethingWithPoint(point) {
    lat = point.lat;
    lng = point.lng;
    console.log(lat, lng);
}

doSomethingWithPoint(london);

14b-pattern-matching-2.coffee

doSomethingWithPoint = ({lat,lng}) ->
    console.log(lat, lng);

doSomethingWithPoint london