CODEWITHSUNDEEP
lodash
Wonka
Wonka

Reputation: 8684

lodash - Sort based on values of different keys?

I have an array of objects, with their quantities (fruit_quantity/vegetable_quantity):

I am trying to sort by those quantities, so it shows the order from highest to lowest with lodash.

var items = [
    {'type': 'fruit', 'name': 'apple', 'fruit_quantity': 20},
    {'type': 'fruit', 'name': 'banana','fruit_quantity': 10},
    {'type': 'vegetable', 'name': 'brocolli','vegetable_quantity': 15},
    {'type': 'fruit', 'name': 'cantaloupe','fruit_quantity': 5}
];

var sortedItems = _.sortBy(items, ['fruit_quantity' || 'vegetable_quantity']).reverse();

I know that if they were the same key, like quantity, then it will be done like this:

var sortedItems = _.sortBy(items, 'quantity').reverse();

But unfortunately I have to use different keys, but still sort with their respective quantity.

Here is a fiddle with my attempt: https://jsfiddle.net/zg6js8af/1/

How can I sort the items by their highest to lowest quantities?

This is what the final sort order should look like:

{'type': 'fruit', 'name': 'apple', 'fruit_quantity': 20},
{'type': 'vegetable', 'name': 'brocolli','vegetable_quantity': 15},
{'type': 'fruit', 'name': 'banana','fruit_quantity': 10},
{'type': 'fruit', 'name': 'cantaloupe','fruit_quantity': 5}

Upvotes: 2

Views: 433

Answers (1)

Ori Drori
Ori Drori

Reputation: 192252

You just need to detect which property exists, and then return it. An example using Array#sort:

var items = [
    {'type': 'fruit', 'name': 'apple', 'fruit_quantity': 20},
    {'type': 'fruit', 'name': 'banana','fruit_quantity': 10},
    {'type': 'vegetable', 'name': 'brocolli','vegetable_quantity': 15},
    {'type': 'fruit', 'name': 'cantaloupe','fruit_quantity': 5}
];

function getQuantity(item) {
  return item.fruit_quantity || item.vegetable_quantity || 0;
}

items.sort(function(a, b) {
  return getQuantity(a) - getQuantity(b);
});

console.log(items);

You can do the same with _.sortBy():

var items = [
    {'type': 'fruit', 'name': 'apple', 'fruit_quantity': 20},
    {'type': 'fruit', 'name': 'banana','fruit_quantity': 10},
    {'type': 'vegetable', 'name': 'brocolli','vegetable_quantity': 15},
    {'type': 'fruit', 'name': 'cantaloupe','fruit_quantity': 5}
];

function getQuantity(item) {
  return item.fruit_quantity || item.vegetable_quantity || 0;
}

var result = _.sortBy(items, getQuantity);

console.log(result);
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>

Upvotes: 3

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