Find max/min value in a Javascript set

Question

I'm developing a Javascript and d3.js application where I'd like to keep track of unique values in a an uploaded dataset. Using one of the new Javascript Set objects seems appealing, but I can't figure out a good way to extract the max and min values of the set. My code:

var mySet = new Set();
mySet.add(5);
mySet.add(10);
mySet.add(20);
console.log( d3.max(mySet) );

This yields undefined rather than 20.

I've tried the .elements(), .values() and .keys() Set functions, which pass a SetIterator object to d3.max() but also return undefined. Using Array.from appears to be currently unsupported in Chrome.

Any suggestions? I realize that this may be browser-specific as Set objects get rolled out; I'm developing on Chrome v44. I've also looked at using an object object as a dictionary, but can't figure out a concise way to get max/min to work with that structure either.

Edit: I initially asked this question using a mix of arrays and numbers as set elements. The issue still appears in Chrome when using just elements, as above

Answer 1

You can find Maximum and Minimum values in one line using apply

const mySet = new Set([1, 2, 9, 7, 8]);
Math.max.apply(this, [...mySet]);
Math.min.apply(this, [...mySet]);

Answer 2

d3.max only takes an array (docs). Right now, you are passing in a set to d3.max that looks like:

{ [5,10,20], 21 }

When you should pass an array like this

[5,10,20,21]

Here's how you should do it:

var mySet = new Set();
mySet.add(5);
mySet.add(10);
mySet.add(20);
mySet.add(21);
myArray = []

// convert set to array
for (v of mySet) {
    myArray.push(v)
}

console.log( d3.max(myArray) );