Filter an array based on another array

Question

I am trying to use Underscore to filter an array based on matches in another array.

I have an array chartOptions.series which looks like this

[{category: "A"}, {category: "B"}, {category: "C"}]

I want to filter this array so that I keep only elements that exist in another array called categoryNames, which looks like this

[0: "A", 1: "B"]

Given this scenario I would expect this result

[{category: "A"}, {category: "B"}]

Here's what I have so far

chartOptions.series = _.filter(chartOptions.series, function(series) {
   return _.where(categoryNames, {"": series.category});
});

This doesn't work, it doesn't filter anything. What am I missing?

[{"A"}, {"B"}] is syntactically invalid. How does it really look? Use JSON.stringify() on it if you're not sure. — Bergi
– Bergi, Commented Jun 5, 2014 at 18:20

hjing · Accepted Answer · 2014-06-05 18:25:03Z

2

Assuming that [0: "A", 1: "B"] is actually ["A", "B"], you can use _.contains:

var categoryNames = ["A", "B"];
_.filter(chartOptions.series, function(series) { 
  return _.contains(categoryNames, series.category) 
});

should do what you want.

answered Jun 5, 2014 at 18:25

hjing

5,0021 gold badge28 silver badges29 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Maybe it is worth to replace contains to categoryNames.indexOf(series.category) >= 0 for simplicity

Haseeb A · Accepted Answer · 2019-04-09 11:50:18Z

0

More modern javascript:

chartOptions.series.filter(series => categoryNames.includes(series.category))

answered Apr 9, 2019 at 11:50

Haseeb A

6,2022 gold badges32 silver badges35 bronze badges