CODEWITHSUNDEEP
javascriptunderscore.jslodash
jiku
jiku

Reputation: 293

Comma-delimited properties to actual properties with Underscore or Lo-Dash

If I have something like

var obj = [{keywords: "a, b, c"}, {keywords: "d, e, f"}]

and do

var result = _.pluck(obj, 'keywords')

I get

result == ['a, b, c', 'd, e, f']

I'd like to have

result == ['a', 'b', 'c', 'd', 'e', 'f']

is there any simple, short way to accomplish that with underscore or lo-dash? Without iterating over result, doing a string split and putting that into a new array?

Upvotes: 0

Views: 1134

Answers (3)

Tomalak
Tomalak

Reputation: 338316

How about

var result = _(obj).pluck('keywords').join().replace(/\s/g, '').split(',');

Edit: A shorter version, ramifications discussed in the comments:

var result = _(obj).pluck('keywords').join().split(/[\s,]+/);

Upvotes: 3

user663031
user663031

Reputation:

Without underscore:

[].concat.apply([], obj.map(function(o) { return o.keywords.split(/[,\s]+/); }))

This takes advantage of the fact that concat does a kind of flattening, in the sense that it adds individual elements in arrays in the argument list to the result.

Upvotes: 2

Mark Reed
Mark Reed

Reputation: 95315

"Without iterating over result, doing a string split and putting that into a new array"?

No; any solution will wind up doing some version of that. You can, however, express that iteration/split/array construction fairly concisely:

_.flatten(_.map(obj, function(o){ return o.keywords.split(/,\s*/) }))

or if you prefer method-chaining:

_.chain(_.map(obj, function(o){ return o.keywords.split(/,\s*/) })).flatten()

but in that case, you might prefer this even more:

_(obj).map(function(o){ return o.keywords.split(/,\s*/) })).flatten()

(This is one of the cases that makes me wish Underscore/LoDash had a flatMap; calling flatten on the result of a regular map destroys any deep structure.)

Upvotes: 1

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