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traversing json objects[Answered]
7 replies
Last post Sep 09, 2019 02:35 PM by EnenDaveyBoy
Last post Sep 09, 2019 02:35 PM by EnenDaveyBoy
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traversing json objects
Sep 07, 2019 01:38 PM|EnenDaveyBoy|LINK
Hi
I am used to doing everythng in c# with lambda linq,and moving to javascript is muddling my mind.
i keep expecting there to be similar options in javascript, i keep getting linked to .find when i google, but thats just for arrays.
so in objs i just have to keep doing loops/iterating is until i get the element i want? and does that make loops/iterating a big thing in js?
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Re: traversing json objects
Sep 07, 2019 01:59 PM|hajan|LINK
Hi there,
Basically, if you have a large list of objects in JavaScript and you have to iterate them, all until you find the match you compare to, it might introduce performance issues. However, if your objects list isn't that big, usually it's pretty much fine to iterate and do comparison until you find the object based on its property value.
Check through this blog post: https://medium.com/backticks-tildes/iterating-through-javascript-objects-5-techniques-and-performance-tests-42b4a222a92b which you may find useful with some nice tips about iterating objects and some performance tips.
Let me know if this has helped.
Thanks,
Hajan
Hajan
Dont forget to the answer which solved your problem!
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Re: traversing json objects
Sep 07, 2019 04:29 PM|bruce (sqlwork.com)|LINK
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array
The global Map and Set object gives you the standard set operations of intersect and product (joins). All the array methods can be used when using map/set.
JavaScript objects are dictionaries in C#. In JavaScript when we use an object as a dictionary it’s called a mapped object (but it’s still just an object). The global Object has methods to return the the properties or keys as arrays. Of course key indexing is supported.
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Re: traversing json objects
Sep 07, 2019 08:33 PM|EnenDaveyBoy|LINK
so if i have want an property value out of the middle of a complex object, do i just loop through all the objects properties moving up the tree, then set the value to a const outside the loop and allow the loop to finish?
just seems a waste, when i get to the node i want, breaking out would reduce wasted traversing, but break causes an error.
most of my items are key:values so don't use arrays 90% of the time.
one of my problems i think is i am using c# terminology to google things, and i get the things which look like they should work but don't because of the array obj difference.
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Re: traversing json objects
Sep 08, 2019 05:10 AM|bruce (sqlwork.com)|LINK
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Re: traversing json objects
Sep 08, 2019 02:20 PM|EnenDaveyBoy|LINK
in the instance i am going at the moment, i can locate the list of objects i am interested in with a key, but then that is a list which i need to reference 3 properties to identify the object i need, hence the loop
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Re: traversing json objects
Sep 09, 2019 09:42 AM|Yang Shen|LINK
Hi EnenDaveyBoy,
Is it possible for you to provide us a demo to tell what exactly you are trying to do or reproduce any problem or are you facing any error?
Best Regard,
Yang Shen
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Re: traversing json objects
Sep 09, 2019 02:35 PM|EnenDaveyBoy|LINK
looks like i was over complicating things, all good now and no where near as complicated.