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CoffeeScript Prototype Error

Here is an example of what I'm trying to do.

User = (name,dob,rank,score) -> 
    {
        name: name
        dob: dob
        details: {
            rank: rank
            score:score 
        }

        basicInfo: -> return "Name: #{@name} - Dob: #{@dob} - #{@details.rank} "
        detailedInfo: -> return "Name: #{@name} - Rank: #{@details.rank} - Score: #{@details.score}"
    }

User::displayName = ->
    console.log @name 

bob = new User("Bob","10/12/69",1,100000)

bob.displayName()

I get the error "Uncaught TypeError: Object # does not have a displayName method"

I don’t know why I get this error. Any help is appreciated.

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2 answers

When you return a new object from the constructor, it does not pass the prototype. A proper constructor adds properties / methods to this:

User = (name,dob,rank,score) -> 
  @name = name
  @dob = dob
  @details =
    rank: rank
    score: score 
  @basicInfo = -> return "Name: #{@name} - Dob: #{@dob} - #{@details.rank} "
  @detailedInfo = -> return "Name: #{@name} - Rank: #{@details.rank} - Score: #{@details.score}"

You might want to use the CoffeeScript abstraction class, which simply generates standard constructor functions:

class User
  constructor: (name, dob, rank, score) ->
    @name = name
    @dob = dob
    @details:
      rank: rank
      score: score 
  basicInfo: ->
    return "Name: #{@name} - Dob: #{@dob} - #{@details.rank} "
  detailedInfo: ->
    return "Name: #{@name} - Rank: #{@details.rank} - Score: #{@details.score}"

, , , basicInfo detailedInfo prototype, . User::displayName = -> console.log @name .

. http://coffeescript.org/#classes

+4

javascript coffeescript. . ( .)

CoffeeScript class , .

class User
    constructor: (@name, @dob) ->

    displayName: ->
        console.log @name

bob = new User "Bob", "10/12/69"

bob.displayName() // "Bob"

: http://coffeescript.org/#classes

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