for (var key in object) in CoffeeScript?

Question

How can I use for (var key in object) in CoffeeScript? It compiles to...

for (_i = 0, _len = object.length; _i < _len; _i++) {
    key = object[_i];

...but I just want to iterate though an object.

score 127 · Accepted Answer · edited Feb 02 '15 at 01:35

127

for key of object

Try it in js2coffee

edited Feb 02 '15 at 01:35

Moox

answered Jun 21 '11 at 23:34

Raynos

11

Also note the `own` keyword to enforce `hasOwnProperty` ... `for own key of object` – jondavidjohn Sep 25 '13 at 22:51
10

Just for anyone else that comes by, it's the `of` keyword that determines looping through arrays vs. objects. – AlbertEngelB Jan 28 '14 at 16:29

score 72 · Answer 2 · 2017-11-13T13:54:52.603

72

of keyword:

for key, value of obj

or to make sure you're only checking properties on this object (and not the prototype chain):

for own key, value of obj

edited Nov 13 '17 at 13:54

answered Jun 21 '11 at 23:32

1

the point of that website is to a) see how I can do a js pattern in coffeescript and b) convert existing js files to coffeescript without re-writing them. – Raynos Jun 21 '11 at 23:36

2 Answers2