underscore to find min and max of object value

Question

As per the tutorial here,

A collection can either be an array or an object, an associate array in JavaScript

does that mean all the functions under collection is equally applicable to object literals. For example, I wanted to pick the values based on a condition. Say,

var obj = {
"1": {id: 1, val: 2},
"2": {id: 2, val: 5},
"3": {id: 3, val: 8},
"4": {id: 4, val: 1}
}

I want to find max and min of val field. Looking at the API, I was thinking to use pluck to get an array of val, then do min and max.

• can I apply pluck to object (as the api example show the use in an array of objects)
• is there a better way?

Thanks.

Answer 1

does that mean all the functions under collection is equally applicable to object literals?

Yes.

can I apply pluck to object (as the api example show the use in an array of objects)

Have you tried it? Yes, you can, but you will get back an array.

is there a better way?

Math.min.apply(null, _.pluck(obj, "val")) (or _.min(_.pluck(obj, "val"))) for getting the minimum value is fine. Yet, if you wanted to get the whole object (with id) you might also use the iterator parameter of min/max:

var lowest = _.min(obj, function(o){return o.val;});