CoffeeScript language Cheat Sheet

A Programming › CoffeeScript cheat sheet in English by apk

CoffeeScript language syntax

Language Development Programming JavaScript Web Intermediate Coffeescript JS

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Installation

Install NodeJs (htttp://nodejs.org/)

Install npm (nodejs included)

npm install coffee-script -g

Usage

~$ coffee src/file.coffee	Run CoffeeScript file
~$ coffee -c -o output/ src/	Compile files from src to output
~$ coffee -e "console.log 'Hello World'"	Evaluate CoffeeScript code
$ coffee --join output/all.js --compile src/*.coffee	Concatenate the source CoffeeScript before compiling
~$ coffee	Start Read-eval-print loop
~$ coffee --output output/ -cw src/	Watch directory src for changes

Variables

language = 'CoffeeScript'

? - Existential Operator

coffee = 'espresso' if morning?

cups = 0; cups ?= 1

sugar = count ? 1

coffee = one?.coffee?().please?.no?.sugar?

Functions

hello = -> console.log "Hello"	define function
hello()	call function
sum = (a, b) -> a + b	define function with args
sum 1, 2	call function with args
sum_multiply = (a, b) -> [ a + b, a * b]	define function
[ sum, multiply ] = sum_multiply 1, 2	call function
myFunc = (param = 'default') -> console.log param	define function with default param
otherFunc = (first, other...) -> conole.log other	define function
otherFunc myArray...	call function with array as arguments

Scope

Notice how all of the variable declarations have been pushed up to the top of the closest scope, the first time they appear. outer is not redeclared within the inner function, because it's already in scope; inner within the function, on the other hand, should not be able to change the value of the external variable of the same name, and therefore has a declaration of its own.

Arrays

array = [1, 2, 3, 4]	Array with numbers from 1 to 4
array = [1...4]	Array with numbers from 1 to 3
array = [1..3]	Array with numbers from 1 to 3
array1 = array[1..3]	Create new array from three items from array
array[1..3] = [3, 2, 1]	Change three items of array
ground_coffee.reverse()	Reverse elements in array
Math.max [12, 32, 11, 67, 1, 3]...	Max element of array
[1 ,2, 3].concat [ 4, 5, 6]	concatenating arrays

Operators and aliases

CoffeeScript	JavaScript
this, @	this
is	===
isnt	!==
not	!
and	&&
or	\|\|
true, yes, on	true
false, no, off	false
of	in
in	find element in array (No JS equivalent)

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Comments (2)

apk 09:24 21 Nov 2015

updated

RSrini 11:11 15 Jul 2015

array = [1....3] Array with numbers from 1 to 4 There is no found dots. only 2 dots and 3 dots available. When i try this the generated array become empty. Please update.