How to iterate over the keys and values in an object in CoffeeScript?

Question

I have an object (an "associate array" so to say - also known as a plain JavaScript object):

obj = {} obj["Foo"] = "Bar" obj["bar"] = "Foo" 

I want to iterate over obj using CoffeeScript as follows:

# CS for elem in obj 

bu the CS code above compiles to JS:

// JS for (i = 0, len = obj.length; i < len; i++) 

which isn't appropriate in this case.

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The JavaScript way would be for(var key in obj) but now I'm wondering: how can I do this in CoffeeScript?

Answer 1

Use for x,y of L. Relevant documentation.

ages = {} ages["jim"] = 12 ages["john"] = 7  for k,v of ages   console.log k + " is " + v 

Outputs

jim is 12 john is 7 

You may also want to consider the variant for own k,v of ages as mentioned by Aaron Dufour in the comments. This adds a check to exclude properties inherited from the prototype, which is probably not an issue in this example but may be if you are building on top of other stuff.