coffee script 学习笔记

learn.coffee

# 变量
number = 2
str = '4'
number = 1 if str

# 变量 数组和objecet处理
[a, b, c] = [1, 2, 3]
{key1, key2} = {key1: 'a', key2: 'b'}

# 方法
fn = (x) -> x*x

# 数组
list = [1,2,3,4,5]

# 对象
config = 
  prefix : 'task'
  fn: fn
  cube: (x) -> x*x

# 方法 多参数
handle = (x, y) ->
  console.log x,y
# 方法 多参数 arguments
handle2 = (x, y...) ->
  print x, y
# 判断是否为空
alert 'I knew it!' if number?

# 数组遍历
cubes = (config.cube number for num in list)

# 数组遍历 ES5
# 区别下面两种

# 正确写法 方法后加空格表示以参数形式传入
cubes =  list.map (ele) ->
  ele * ele

# 错误写法
cubes = list.map(x) ->
  x * x

# coffee script 一些技巧写法
numbers = [1,2,3,4,5]

# 从0开始取2个 包含第2个
start = numbers[0..2]

# 从0开始取2个 不包含第2个
start = numbers[0...2]

# 复制
copy = numbers[..]

# 替换数组从3-5 包含5的值
numbers[3..5] = ['x', 'y', 'z']

# 替换数组从3-5 不包含5的值
numbers[3...5] = ['x', 'y']

# 替换数组
# target: Array
# replate: Array
# start: init
replaceArr = (target, replace, start) ->
  end = start  + replace.length
  target[start..end] = replace
  target

# 表达式
getTask = (config) ->
  if config.task
    'getTask'
  else if config.project
    pid = config.project.id
    if pid
    then pid
    else 'getProject'

# 遍历window 获取globals的前10项
globales = (name for name of window)[0..10]

# class
class Point
  constructor: (@name) ->
  move: (meters) ->
    alert @name + "moved #{meters}"
    @