How can I remove values from array with lodash?

Question

I am trying to remove the undefined values from this array: [undefined, "een", "twee", undefined]. The collection is an object like this:

{container:{id:1},container2:{id:2},container3:{pid:2}}

This does not work:

_.remove(_.map(collection,'id'),"undefined")

How can I do it?

undefined and "undefined" are not the same thing. _.remove(_.map(collection,'id'), undefined); works. Voting to close as typo. — Amadan
– Amadan, Commented Dec 15, 2016 at 1:37
.filter also removes other untruthy values like false and 0 — fregante
– fregante, Commented Dec 15, 2016 at 1:53

P Varga · Accepted Answer · 2016-12-15 01:40:35Z

2

Try _.without(_.map(collection, 'id'), undefined).

_.remove() returns the removed items.

answered Dec 15, 2016 at 1:40

P Varga

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Comments

Dmitry · Accepted Answer · 2017-05-06 18:57:07Z

0

For an array, you can use _.compact([NaN, 1, 0, 2, null, 5, undefined, 4]) to remove all falsey values, which will produce [1, 2, 5, 4]

In case your collection is an object, you can use

_.pickBy({foo: 'bar', baz: undefined}, _.identity)

to achieve a similar result: {foo: 'bar'}.

Of course, you can always use any other function instead of _.identity if you have more complex logic.

I would also suggest looking at _.remove() depending on your needs.

Also, everything can be achieved with _.filter,_.map,_.reduce.

Good luck!

answered May 6, 2017 at 18:57

Dmitry

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