Skip to main content

Timeline for Loop through an array in JavaScript

Current License: CC BY-SA 4.0

45 events
when toggle format what by license comment
Sep 20, 2023 at 17:22 comment added Chema ESLint complains about for..of, by default: «iterators/generators require regenerator-runtime, which is too heavyweight for this guide to allow them. Separately, loops should be avoided in favor of array iterations [eslintno-restricted-syntax]». I'm tempted to forget all this madness, and stick exclusively to while...
Jun 18, 2023 at 18:24 comment added Gleichmut This answer has in-deep explanation of this topic: stackoverflow.com/questions/9329446/…
May 22, 2023 at 20:09 comment added horace I'm not thrilled with forEach. for-of is much more clear semantically. Think of the next programmer: not everyone is at the same level skill-wise. Who cares about performace? So long as you are searching millions of nodes and/or subnodes in some kind of tree, or doing thousands of searches every minute. But most apps don't fit into that category.
Mar 21, 2023 at 6:38 comment added PHP Guru If you know that an array is sparse, for...in has the benefit of only iterating over existing keys without the need for the syncronous function callback needed by forEach. For...in is also compatible with old browsers. Don't dis for...in. As of ES5 for...in iterates over array keys first before any other properties.
Aug 31, 2022 at 12:15 comment added Newbie... What about performance-wise?
Jul 2, 2022 at 17:19 comment added cprcrack I prefer for...of instead of forEach() because for...of doesn't use a callback and that can really help with Typescript type inference: stackoverflow.com/a/72841021/423171
May 27, 2022 at 5:42 comment added Adam I think the mentioned contra of missing "continue" is not really true, just use return inside the functions, its the equivalent. However, the missing "break" is a valid contra point.
May 14, 2022 at 16:32 comment added Scotty Jamison For those looking at this answer and wondering whether they should choose forEach() of for-of, I would just recommend using for-of. for-of is the newer looping syntax that entirely replaces the need for forEach. There isn't anything that for-of offers that forEach does not, but the inverse isn't true.
May 14, 2022 at 16:28 comment added Scotty Jamison For reference, this is how to get the current index as you loop. I personally find this pretty straightforwards. for (const [i, x] of yourArray.entries()) { ... }.
Mar 14, 2022 at 21:41 comment added Jason 'Slingshot' Miller What about the for(let ojb of objs) statement?
Feb 16, 2022 at 18:23 comment added Alvaro Carvalho @Vic you can, but it's not straightforward.
Sep 9, 2021 at 1:13 comment added Vic con of es6 for-of: can't get the current index
Jun 15, 2021 at 11:41 comment added bmaupin I know this answer predates async and Promises, but I feel this is worth mentioning in any conversation pertaining to modern JavaScript: "forEach does not wait for promises. Make sure you are aware of the implications while using promises (or async functions) as forEach callback." (developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/…)
May 29, 2021 at 4:15 history rollback user229044♦
Rollback to Revision 19
May 29, 2021 at 1:41 history edited dthree CC BY-SA 4.0
Added examples and benchmark of options.
May 8, 2021 at 7:37 history edited Mateen Ulhaq CC BY-SA 4.0
Simplify arrow function
May 8, 2021 at 7:31 history edited Mateen Ulhaq CC BY-SA 4.0
Short summary at top.
Nov 10, 2020 at 2:42 review Suggested edits
Nov 10, 2020 at 11:48
Oct 6, 2020 at 12:54 history edited Peter Mortensen CC BY-SA 4.0
Active reading [<https://en.wikipedia.org/wiki/Sentence_clause_structure#Run-on_sentences> (see also <https://twitter.com/PeterMortensen/status/1199839973215739907>) ]. Added some context. Expanded.
Jun 20, 2020 at 9:12 history edited CommunityBot
Commonmark migration
S Jun 7, 2020 at 20:56 history suggested Zamomin CC BY-SA 4.0
fixed grammar, removed repeated phrase
Jun 7, 2020 at 13:36 review Suggested edits
S Jun 7, 2020 at 20:56
S Jan 16, 2020 at 1:13 history suggested CommunityBot CC BY-SA 4.0
Fixed indenting
Jan 15, 2020 at 23:01 review Suggested edits
S Jan 16, 2020 at 1:13
Nov 22, 2019 at 13:09 history edited Christian C. Salvadó CC BY-SA 4.0
fix grammar errors and typos
S Aug 30, 2019 at 14:53 history suggested Sapphire_Brick CC BY-SA 4.0
proofread a little more, also clarified "off-by-one-error"
Aug 30, 2019 at 13:30 review Suggested edits
S Aug 30, 2019 at 14:53
Jul 11, 2019 at 18:54 history edited Jonathan Hall CC BY-SA 4.0
edited body
May 29, 2019 at 17:21 history edited Christian C. Salvadó CC BY-SA 4.0
Added executable examples, added map and reduce examples and antipatterns
May 16, 2019 at 17:23 history edited Christian C. Salvadó CC BY-SA 4.0
update answer, add ES5 forEach, ES6 for-of, pros / cons
S Feb 15, 2019 at 9:06 history suggested Jonathan CC BY-SA 4.0
internal fiddle
Feb 15, 2019 at 8:44 review Suggested edits
S Feb 15, 2019 at 9:06
Dec 4, 2018 at 22:09 review Suggested edits
Dec 4, 2018 at 22:36
Oct 24, 2018 at 6:46 review Suggested edits
Oct 24, 2018 at 7:26
Dec 26, 2017 at 15:12 review Suggested edits
Dec 26, 2017 at 18:19
Aug 17, 2017 at 12:31 review Suggested edits
Aug 17, 2017 at 14:23
Sep 26, 2014 at 21:02 history edited Jonathan Hall CC BY-SA 3.0
added 7 characters in body
Feb 24, 2014 at 20:10 history edited MonkeyZeus CC BY-SA 3.0
added 36 characters in body
S Jun 21, 2013 at 15:03 history suggested Johann CC BY-SA 3.0
Fix external link by pointing to http://web.archive.org/
Jun 21, 2013 at 15:03 review Suggested edits
S Jun 21, 2013 at 15:03
Apr 30, 2013 at 13:31 history edited suspectus CC BY-SA 3.0
deleted 2 characters in body
Jun 10, 2010 at 2:41 vote accept Mark Szymanski
Jan 6, 2012 at 18:53
Jun 10, 2010 at 0:28 history edited Christian C. Salvadó CC BY-SA 2.5
added 386 characters in body
Jun 10, 2010 at 0:16 history edited Christian C. Salvadó CC BY-SA 2.5
added 588 characters in body; added 399 characters in body
Jun 10, 2010 at 0:07 history answered Christian C. Salvadó CC BY-SA 2.5
toggle format