coffeescript - 默认函数参数排序

Question

通读this ，我开始讨论函数参数的默认值:

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

这很好，但后来我尝试了这个:

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

alert fill(liquid="juice")

并收到意外警报:“正在用咖啡填充果汁...”。然后我尝试了这个:

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

alert fill(null, "juice")

并且成功了。但它并不漂亮。有没有更好的方法，或者这是执行此操作的惯用方法？

Answer 1

fill = ({container, liquid} = {}) ->
     container ?= "mug"
     liquid ?= "coffee"

     "Filling the #{container} with #{liquid}..."

alert fill(liquid: "juice", container: "glass")
alert fill()

fill = (quantity="500 mL", {container, liquid} = {}) ->
     container ?= "mug"
     liquid ?= "coffee"

     "Filling the #{container} with #{quantity} of #{liquid}..."

alert fill("1L", liquid: "juice", container: "glass")
alert fill()
alert fill "1L"
alert fill "1L", liquid: "water"