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5 Must Know Lodash Methods

Cameron Lucas on July 28, 2021

Lodash is a Javascript utility library, that helps you work with arrays, objects, strings, and just write fewer functions in general. Let's talk Lo...
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Jon Randy 🎖️

I'm confused - most, if not all of the examples above can be achieved using less code in plain JS - without the overhead of a library. Using plain JS will also be faster. The debounce one is quite useful, but again - easy to write yourself instead of including a whole library

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Jon Randy 🎖️ • Edited

1.

const myFavCandy = foodObj ?. favFoods[3] ?. favCandy || 'Chocolate'
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2.

const myNewBestFriend = adoptableDogs.find(dog => dog.breed=="White Lab" && dog.age>2)
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3.

const adoptableDogsNames = adoptableDogs.map(dog => dog.name)
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4.

adoptableDogs[2].age = 1
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No 72.5Kb of lodash even remotely required

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fxbit profile image
Petros Vasileiou

In general for this simple cases yes you don't need lodash, but in more real complex applications is simplify many things especially the chaining.

For example in 1 and 4 when you don't know in compile time the "path", but is something that is user/api/external input how you are going to do it ?

One other thing that I like in lodash is the internal error checking and handling. For example the 2 and 3 example if the adoptableDogs is null/undefined the code is going to get exception, you need to check it before use it.
The lodash is going to return empty array in map and null in find, a consistent result that you don't need to have special check or path in your code flow.

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jonrandy profile image
Jon Randy 🎖️

I agree. I was merely pointing out that these were poor examples, that do not really give any idea of why, and in what situations Lodash can be beneficial

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Jesse Warden

Some points:

  1. 4 is doing mutation. In Lodash, set safely gives you a new object (not deep clone, but property copy)
  2. 1 - 4 cannot be curried in normal JavaScript unless you manually wrap them. When you start composing functions, whether using Promise, your own composition, or the new pipeline operator, you end up wrapping all this stuff.
const map_ = func => array => array.map(func)
const find_ = func => array => array.find(func)
["1", "2", "3"]
|> map_(parseInt)
|> find_(isEven)
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  1. You can re-use the partially applied functions in 2; creating these yourself just to re-use is tiresome.
  2. Not all JavaScript supports this. Many of us still deal with various IE or old Node.js versions that can't be upgraded yet. #inb4Babel This is why we use Lodash, not just 5 methods that happen to have equivalent features in "the latest JS". We agree with you that if you have that ability in the browser or your current version of Node.js, yes yes, totally use the native functionality.
  3. Outside of AWS Lambda, filesize doesn't matter in Node.js.
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jonrandy profile image
Jon Randy 🎖️ • Edited

So, the writer's example for number 4 then does not even work? The way the example is written implies mutation. This adds even more weight to my contention that these are poor Lodash examples

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Jesse Warden • Edited

No it works, he imported map form lodash, not lodash/fp. Most people when starting to learn will start with Lodash, and that works great for many years. Those who want curry first, data last style coding can use lodash/fp when they are ready (if they want, no pressure). All the same imports, but the parameter order is usually reversed.

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jonrandy profile image
Jon Randy 🎖️

Ah ok, your comments were referencing a functional version of Lodash

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jesterxl profile image
Jesse Warden

Sort of, it's kind of confusing and frustrating.

Like, Lodash makes it pretty clear some methods mutate the original Array/Object, while others return shallow copies. You'd assume the FP version would, but that's not always the case, so... it's kind of FP, which is better than nothing; at least they document it.

For things like set, though, thankfully, they work the same in both lodash and lodash/fp; it returns a "new"ish Object without mutation.

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jonrandy profile image
Jon Randy 🎖️

So the writer's example doesn't work

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jesterxl profile image
Jesse Warden

Why you gotta be a troll, man? Guy is just trying to show how cool Lodash is.

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jonrandy profile image
Jon Randy 🎖️

Not trolling. His examples don't show how good Lodash is, and - as we've established - the fourth example doesn't work if what you said about set not mutating is correct

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Sergio Martín

All those "modern JS" native methods did not exist when Lodash was first conceptualized....

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Cameron Lucas • Edited

You are not wrong! Lodash has a bunch of methods that just make doing certain tasks easier. Adding Lodash to your Javascript project adds these methods some other frameworks like Django or Ruby on Rails would have out of the box. Such as the zip method in Ruby on Rails which will zip together two arrays into one. Javascript doesn't have this functionality out of the box... Lodash has a _.zip method. Don't get me wrong you could also do this with the array .map method in Javascript. As for the library overhead you could always import each method individually.

Ex. const zip = require("lodash/zip");

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Mike Talbot ⭐ • Edited

You certainly should only import the modules you use, otherwise a few convenience methods are taking up more space than whole frameworks like React. Functions such as debounce() in lodash have tons of options that make them much heavier than lightweight implementations (which are mostly what it is used for) - if you aren't using the options for trailing and leading edges, it's costing "something".

For me in big apps that are likely to use lots of utility methods over time, I'd take Sugar.js because that has some really useful functions - like Date.create("Next monday at 2pm"), debounce etc. It's also 1/3 the size of lodash if you include it all (and you don't have to).

sugar

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Jon Randy 🎖️

Probably would have been better to show examples of where using Lodash would actually have some benefit

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Cameron Lucas

Maybe in my next post! 😉 say tuned lol!

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Jon Randy 🎖️ • Edited

'Tuned'

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murkrage profile image
Mike Ekkel

I see what you did there 👀

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bukazoltan profile image
bukazoltan

I don't know anything about ruby on rails but isn't that concat? w3schools.com/jsref/jsref_concat_a...

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Cameron Lucas

It's a little different concat would join the two arrays. So if you had [1, 3, 5] and [2, 4]. The results of concatenation would be [1, 3, 5, 2, 4]. The zip method would zip the two arrays together like a zipper. The results would look like this [1, 2, 3, 4, 5]

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bukazoltan profile image
bukazoltan

So basically concat + sort?

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leob profile image
leob

I think you have a point especially on the client - downloading dozens of extra KB's is not a good idea unless it's really necessary ... server side (node.js) this is less of an issue.

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Sebastian Vargr • Edited

Recommendation: Do not use Lodash in current year.

Like others here have pointed out, It is a literal waste of kb's in your payload. :)

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Ondřej Želazko • Edited

well, import { debounce } from 'lodash'; kinda takes your argument away (there are even separate packages for everything). also, in past years I'd been writing my own debounce function in every project, it isn't that a complex mechanism. I'm not that foolish any more. the lodash's version is superior and documented. and that's gist of it.

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Sebastian Vargr

debouncing is not Lodash tho, it’s part of the library by practical coincidence.

It could also be a separate package like you point out.

Lodash was made in an age when array methods where lacking and polyfiling was less common.

If they changed the focus of the library, then I did not get the memo. :)

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tanth1993

in Lodash, I use debounce and cloneDeep most :)