Map over object preserving keys

Question

The map function in underscore.js, if called with a javascript object, returns an array of values mapped from the object\'s values.

_.map({one:          


        

Answer 1

_.map returns an Array, not an Object.

If you want an object you're better off using a different function, like each; if you really want to use map you could do something like this:

Object.keys(object).map(function(value, index) {
   object[value] *= 3;
})

but that is confusing, when seeing map one would expect to have an array as result and then make something with it.