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Hi Gus,
Using a Map over an Object is very often a wise choice but for some reason one I seldom employ; I have no justification other than set in my ways.
One thing to consider is JSON, Objects are supported directly but Maps are not.
Regards, Tracy
Hey Tracy! Good to see you here.
The same goes for me. That is one of the reasons why I wrote the post haha.
There is also the case where most of your colleagues might not be used to it, than you'd prefer to stick with regular objects not to raise eyebrows haha..
Thanks for stopping by again, and have a great week!
Isn't speed/performance another reason to prefer Map? I've heard that Map is faster with lookups, especially when the number of items is larger.
Hey Leopb! how are you? thanks for leaving a comment!
You're right, Map seems to be faster in most cases, specially for reading.
There is a video in the first section with some tests.
Have a great week my dude!
The video doesn't actually cover a
map.get(key: string)vsobjectMap.keyaccess comparison.Given the impact that performance of the
object.propertylookup has on the overall JS runtime performance I would be surprised ifmap.get(key: string)is faster thanobject.propertyfor lookup over a[key, value]set not exceeding the size of the number of properties found on a typical object.Map is optimized for
[key, value]deletion and insertion (while maintaining the insertion order for iteration which is something objects per spec don't guarantee even though they often do) and efficiently handling larger[key, value]sets.Meanwhile an object literal lookup will often perform similar to a
switchstatement on a string value.Hey Peerreynders! Thanks for you insighful comment!
Apperantly Map outperforms Object in all operations unless you have small integer, array-indexed keys according to this article that run multiple tests.
Have an awesome week!
The article discusses insertion, deletion, and iteration performance, the scenarios Map is specifically optimized for. Lookup/access performance isn't discussed.
In this test objects are faster on Chrome 109 (V8) while maps are faster on Firefox 109.0 (SpiderMonkey). But once the number of entries increases to 20-30 map performance catches up.
I didn't know about the jsbench website! Thanks for sharing the link Peerreynders!
That is an in-depth test.
Thanks once again.
Great post! No native serialization is a big downside though. In modern apps, a lot of data structures go from/to Json APIs, so having data structures with native serialization is extremely convenient. The benefits are there, but only for data that doesn't need to be serialized I think.
Hey Rense! thanks for stopping by.
100% with you, no native serialization/parsing is a big downside. That's one of the reasons I'd choose plain objects.
Have a great week!
Great post, it's clear that you have a lot of experience and knowledge about the topic. Your examples and explanations make it easy to understand the differences between Map and Object.
Have you tried experimenting with the different use cases of Map and Object in your projects? It would be great to see some examples of how you have utilized these data structures in your own work.
Hey Elliot! how are you? Thanks for taking the time to comment!
I am not that experienced at all lol. I am just curious.
And yes I have used it a few times. The second example at the end of the post is actual code I used in a project I build when buidling my portfolio.
Have a great week man!
Great research and article 🎉
Thanks a lot Rai! Happy to hear it
Very nice article, thanks a lot! I will use
Mapand see how that goes.I am happy that you liked it Franco! Come back and let me know how it went
Great post with good examples and explanations
I am super glad you found it useful Easyjobber!
Passe une bonne semaine!
Thank you for the post! I don't didn't really understand the difference until reading this. I definitely assumed they were the same thing.
I am happy to hear that my post helped to clarify the differences Andre!
That is what makes my day.
Thanks for taking the time to leave a comment and have an awesome week.
Nice explanation. Maps don't allow duplicates. Which is a good reason to use them sometimes.
Did not known about new object(null)
Good to know.
Thanks
Hey Frakie Tap! I am glad you got some value out of it.
Thanks for taking the time to leave a comment!
have a great week my dude
Nice work Gus,
I imagine using a map with my key and/or values as functions if the exact their values needs to be calculated at a later time in my logic?... still thinking
Hey Niza!! thanks for leavaving a comment man!
Not 100% sure what you mean though.. haha
Have a great week man
One of the best articles so far. Was waiting for this.
Wow, you just made my day Bidisha!
I am glad it was helpful!
See you around.
map is more like an array and modern data type.
Thanks for commenting Al-waisy!
Helpful article @gustavupp
I am very glad it was helpful Kumar!
Thanks
Thank you Ernazar for leaving a comment!
Hey I think you've missed a very important point.
Under the hood objects strongly favor static vs dynamic shapes/size. This means that adding or deleting keys in objects is very slow compared to maps which are designed for exactly this.
except for a few things(non-technical), great post and also great informative comments