CODEWITHSUNDEEP
underscore.jslodash
port5432
port5432

Reputation: 6381

Underscore instead of a for loop

Given I have an array like this

var arr = [ { "language" : "en", "level" : "C2", "primary" : true }, 
            { "language" : "fr", "level" : "B1", "learning" : true }, 
            { "language" : "it", "level" : "A2" } ]

I want to collect all the "language" values into a single array, like this:

["en", "fr", "it"]

I know I can do it with a for loop, but how would I do it with Underscore / LoDash?

How would I order by one of the boolean fields, and then alpha ie: if ordering by the "learning" boolean:

["fr", "en", "it"]

Upvotes: 0

Views: 43

Answers (1)

Kiril
Kiril

Reputation: 2963

Use the combination of _.sortByAll and _.pluck functions (link to jsbin):

var arr = [ { "language" : "en", "level" : "C2", "primary" : true }, 
            { "language" : "fr", "level" : "B1", "learning" : true }, 
            { "language" : "it", "level" : "A2" } ];

var res = _.pluck(_.sortByAll(arr, 'learning', 'language'), 'language');

console.log(res);

.sortByAll will sort your array firt by learning field and then by language. And .pluck will take the given field from every object in the array (language in your case).

Upvotes: 2

Related Questions