CoffeeScript 是一门编译到 JavaScript 的小巧语言. 在 Java 般笨拙的外表下, JavaScript 其实有着一颗华丽的心脏. CoffeeScript 尝试用简洁的方式展示 JavaScript 优秀的部分.

CoffeeScript 的指导原则是: "她仅仅是 JavaScript". 代码一一对应地编译到 JS, 不会在编译过程中进行解释. 已有的 JavaScript 类库可以无缝地和 CoffeeScript 搭配使用, 反之亦然. 编译后的代码是可读的, 且经过美化, 能在所有 JavaScript 环境中运行, 并且应该和对应手写的 JavaScript 一样快或者更快.

# 赋值:
number   = 42
opposite = true# 条件:
number = -42 if opposite# 函数:
square = (x) -> x * x# 数组:
list = [1, 2, 3, 4, 5]# 对象:
math =root:   Math.sqrtsquare: squarecube:   (x) -> x * square x# Splats:
race = (winner, runners...) ->print winner, runners# 存在性:
alert "I knew it!" if elvis?# 数组 推导(comprehensions):
cubes = (math.cube num for num in list)

var cubes, list, math, num, number, opposite, race, square,__slice = [].slice;number = 42;opposite = true;if (opposite) {number = -42;
}square = function(x) {return x * x;
};list = [1, 2, 3, 4, 5];math = {root: Math.sqrt,square: square,cube: function(x) {return x * square(x);}
};race = function() {var runners, winner;winner = arguments[0], runners = 2 <= arguments.length ? __slice.call(arguments, 1) : [];return print(winner, runners);
};if (typeof elvis !== "undefined" && elvis !== null) {alert("I knew it!");
}cubes = (function() {var _i, _len, _results;_results = [];for (_i = 0, _len = list.length; _i < _len; _i++) {num = list[_i];_results.push(math.cube(num));}return _results;
})();

square = (x) -> x * x
cube   = (x) -> square(x) * x

var cube, square;square = function(x) {return x * x;
};cube = function(x) {return square(x) * x;
};

fill = (container, liquid = "coffee") ->"Filling the #{container} with #{liquid}..."

var fill;fill = function(container, liquid) {if (liquid == null) {liquid = "coffee";}return "Filling the " + container + " with " + liquid + "...";
};

song = ["do", "re", "mi", "fa", "so"]singers = {Jagger: "Rock", Elvis: "Roll"}bitlist = [1, 0, 10, 0, 11, 1, 0
]kids =brother:name: "Max"age:  11sister:name: "Ida"age:  9

var bitlist, kids, singers, song;song = ["do", "re", "mi", "fa", "so"];singers = {Jagger: "Rock",Elvis: "Roll"
};bitlist = [1, 0, 1, 0, 0, 1, 1, 1, 0];kids = {brother: {name: "Max",age: 11},sister: {name: "Ida",age: 9}
};

$('.account').attr class: 'active'log object.class

$('.account').attr({"class": 'active'
});log(object["class"]);

outer = 1
changeNumbers = ->inner = -1outer = 10
inner = changeNumbers()

var changeNumbers, inner, outer;outer = 1;changeNumbers = function() {var inner;inner = -1;return outer = 10;
};inner = changeNumbers();

mood = greatlyImproved if singingif happy and knowsItclapsHands()chaChaCha()
elseshowIt()date = if friday then sue else jill

var date, mood;if (singing) {mood = greatlyImproved;
}if (happy && knowsIt) {clapsHands();chaChaCha();
} else {showIt();
}date = friday ? sue : jill;

gold = silver = rest = "unknown"awardMedals = (first, second, others...) ->gold   = firstsilver = secondrest   = otherscontenders = ["Michael Phelps""Liu Xiang""Yao Ming""Allyson Felix""Shawn Johnson""Roman Sebrle""Guo Jingjing""Tyson Gay""Asafa Powell""Usain Bolt"
]awardMedals contenders...alert "Gold: " + gold
alert "Silver: " + silver
alert "The Field: " + rest

var awardMedals, contenders, gold, rest, silver,__slice = [].slice;gold = silver = rest = "unknown";awardMedals = function() {var first, others, second;first = arguments[0], second = arguments[1], others = 3 <= arguments.length ? __slice.call(arguments, 2) : [];gold = first;silver = second;return rest = others;
};contenders = ["Michael Phelps", "Liu Xiang", "Yao Ming", "Allyson Felix", "Shawn Johnson", "Roman Sebrle", "Guo Jingjing", "Tyson Gay", "Asafa Powell", "Usain Bolt"];awardMedals.apply(null, contenders);alert("Gold: " + gold);alert("Silver: " + silver);alert("The Field: " + rest);

# 吃午饭.
eat food for food in ['toast', 'cheese', 'wine']# 精致的五道菜.
courses = ['greens', 'caviar', 'truffles', 'roast', 'cake']
menu i + 1, dish for dish, i in courses# 注重健康的一餐.
foods = ['broccoli', 'spinach', 'chocolate']
eat food for food in foods when food isnt 'chocolate'

var courses, dish, food, foods, i, _i, _j, _k, _len, _len1, _len2, _ref;_ref = ['toast', 'cheese', 'wine'];
for (_i = 0, _len = _ref.length; _i < _len; _i++) {food = _ref[_i];eat(food);
}courses = ['greens', 'caviar', 'truffles', 'roast', 'cake'];for (i = _j = 0, _len1 = courses.length; _j < _len1; i = ++_j) {dish = courses[i];menu(i + 1, dish);
}foods = ['broccoli', 'spinach', 'chocolate'];for (_k = 0, _len2 = foods.length; _k < _len2; _k++) {food = foods[_k];if (food !== 'chocolate') {eat(food);}
}

countdown = (num for num in [10..1])

var countdown, num;countdown = (function() {var _i, _results;_results = [];for (num = _i = 10; _i >= 1; num = --_i) {_results.push(num);}return _results;
})();

yearsOld = max: 10, ida: 9, tim: 11ages = for child, age of yearsOld"#{child} is #{age}"

var age, ages, child, yearsOld;yearsOld = {max: 10,ida: 9,tim: 11
};ages = (function() {var _results;_results = [];for (child in yearsOld) {age = yearsOld[child];_results.push("" + child + " is " + age);}return _results;
})();

# 经济 101
if this.studyingEconomicsbuy()  while supply > demandsell() until supply > demand# 摇篮曲
num = 6
lyrics = while num -= 1"#{num} little monkeys, jumping on the bed.One fell out and bumped his head."

var lyrics, num;if (this.studyingEconomics) {while (supply > demand) {buy();}while (!(supply > demand)) {sell();}
}num = 6;lyrics = (function() {var _results;_results = [];while (num -= 1) {_results.push("" + num + " little monkeys, jumping on the bed. One fell out and bumped his head.");}return _results;
})();

for filename in listdo (filename) ->fs.readFile filename, (err, contents) ->compile filename, contents.toString()

var filename, _fn, _i, _len;_fn = function(filename) {return fs.readFile(filename, function(err, contents) {return compile(filename, contents.toString());});
};
for (_i = 0, _len = list.length; _i < _len; _i++) {filename = list[_i];_fn(filename);
}

numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9]start   = numbers[0..2]middle  = numbers[3...-2]end     = numbers[-2..]copy    = numbers[..]

var copy, end, middle, numbers, start;numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9];start = numbers.slice(0, 3);middle = numbers.slice(3, -2);end = numbers.slice(-2);copy = numbers.slice(0);

numbers = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]numbers[3..6] = [-3, -4, -5, -6]

var numbers, _ref;numbers = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];[].splice.apply(numbers, [3, 4].concat(_ref = [-3, -4, -5, -6])), _ref;

grade = (student) ->if student.excellentWork"A+"else if student.okayStuffif student.triedHard then "B" else "B-"else"C"eldest = if 24 > 21 then "Liz" else "Ike"

var eldest, grade;grade = function(student) {if (student.excellentWork) {return "A+";} else if (student.okayStuff) {if (student.triedHard) {return "B";} else {return "B-";}} else {return "C";}
};eldest = 24 > 21 ? "Liz" : "Ike";

six = (one = 1) + (two = 2) + (three = 3)

var one, six, three, two;six = (one = 1) + (two = 2) + (three = 3);

# 前十个全局属性(变量).globals = (name for name of window)[0...10]

var globals, name;globals = ((function() {var _results;_results = [];for (name in window) {_results.push(name);}return _results;
})()).slice(0, 10);

alert(trynonexistent / undefinedcatch error"And the error is ... #{error}"
)

var error;alert((function() {try {return nonexistent / void 0;} catch (_error) {error = _error;return "And the error is ... " + error;}
})());

launch() if ignition is onvolume = 10 if band isnt SpinalTapletTheWildRumpusBegin() unless answer is noif car.speed < limit then accelerate()winner = yes if pick in [47, 92, 13]print inspect "My name is #{@name}"

var volume, winner;if (ignition === true) {launch();
}if (band !== SpinalTap) {volume = 10;
}if (answer !== false) {letTheWildRumpusBegin();
}if (car.speed < limit) {accelerate();
}if (pick === 47 || pick === 92 || pick === 13) {winner = true;
}print(inspect("My name is " + this.name));

solipsism = true if mind? and not world?speed = 0
speed ?= 15footprints = yeti ? "bear"

var footprints, solipsism, speed;if ((typeof mind !== "undefined" && mind !== null) && (typeof world === "undefined" || world === null)) {solipsism = true;
}speed = 0;if (speed == null) {speed = 15;
}footprints = typeof yeti !== "undefined" && yeti !== null ? yeti : "bear";

CoffeeScript 是一门编译到 JavaScript 的小巧语言. 在 Java 般笨拙的外表下, JavaScript 其实有着一颗华丽的心脏. CoffeeScript 尝试用简洁的方式展示 JavaScript 优秀的部分.

CoffeeScript 的指导原则是: "她仅仅是 JavaScript". 代码一一对应地编译到 JS, 不会在编译过程中进行解释. 已有的 JavaScript 类库可以无缝地和 CoffeeScript 搭配使用, 反之亦然. 编译后的代码是可读的, 且经过美化, 能在所有 JavaScript 环境中运行, 并且应该和对应手写的 JavaScript 一样快或者更快.