CoffeeScript is a programming language created by Jeremy Ashkenas that transpires to JavaScript. It aims to enhance JavaScript with syntax sugar like lambda functions, list comprehensions, and class definitions. CoffeeScript code reads like English and removes unnecessary characters like semicolons and parentheses from JavaScript. Classes in CoffeeScript are based on JavaScript's prototype-based inheritance, and new objects created with the new keyword link to the class's prototype for property lookup.

1. https://youtu.be/DspYurD75Ns?t=43
CoffeeScript

2. CoffeeScript
created by Jeremy
Backbone.js
transpile to ES5
Syntax Sugar
adopted by
node.js
Ruby

3. Less is More
var ; () {}

4. Lambda (arrow)
Callback function is simple.

5. Slice Splats…

6. Comprehension
if, for generates list
list.filter(item != 2).map(item => print item)
for (item <- list; item != 2) yield print item

7. Operator Alias
Write codes like speaking English.
on, yes -> true
is -> ===

8. Class
class Car
name: “Prius”
mycar: ->
console.log “My car is #{@name}”
c1 = new Car()
c1.mycar() // “My car is Prius”

9. Prototype base class :
JS class is based on prototype based OOP

10. Prototype Property
{}c1 = new Car() new create a blank object {}
and a link to Car.prototype
Car = function() {
// prototype is created implicitly
}
Car.prototype.name = “Prius”
c1.name Prototype Chain
look up prototype.name if name does not exist.

11. this
c1 = new Car()
{
name : “Prius”,
mycar : function()…
}
Car = function() {
this.name = “Prius”
this.mycar = function()
}
Window.name = “Prius”
c2 = new Car()
{
name : “Prius”,
mycar : function()…
}
c3 = Car()

12. Copy on write
Car.prototype
c1 = new Car()
{name : “Prius x”}
{
name : “Porche”,
mycar : function()…
}
c1.name = “Prius x”
{}
c2 = new Car()
creates a prop name in c1