Sorting the results of _.countBy - sorting

Question

I have a collection (Products) and I use _.countBy like this :
var totalByBrand = _.countBy(result, "Brand");
and I have this result :
{
'Brand 1 ' : 5,
'Brand 2 ' : 45,
'Brand 3 ' : 2,
...
'Brand 99 ' : 25
}
I try to sort this result to obtain that :
{
'Brand 3 ' : 2,
'Brand 1 ' : 5,
'Brand 99 ' : 25,
...
'Brand 2 ' : 45
}
Is it possible with _.sortBy() ?

Answer 1

Properties order cannot be guaranteed in JavaScript Does JavaScript Guarantee Object Property Order? and that means you can't sort them.
You would have to use a different structure, maybe a list of objects like {brand: ..., count: ...} and sort on on count. For example
var totalByBrand = _.countBy(products, 'Brand');
var sorted = _.chain(totalByBrand).
map(function(cnt, brand) {
return {
brand: brand,
count: cnt
}
})
.sortBy('count')
.value();
And a demo
var products = [
{Brand: "Brand 1", id: 1},
{Brand: "Brand 1", id: 2},
{Brand: "Brand 2", id: 3},
{Brand: "Brand 3", id: 4},
{Brand: "Brand 3", id: 5},
{Brand: "Brand 1", id: 6},
];
var totalByBrand = _.countBy(products, 'Brand');
var sorted = _.chain(totalByBrand).
map(function(cnt, brand) {
return {
brand: brand,
count: cnt
}
}).sortBy('count')
.value();
console.dir(
sorted
);
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