Remove property for all objects in array

Question

I want to remove the bad property from every object in the array  Is there a better way to do it than using a for loop and deleting it from every object   var array      bad    something    good   something     bad   something    good   something          for  var i   0  len   array length  i  lt  len  i        delete array i  bad      Just seems like there should be a way to use prototype  or something  I don   t know  Ideas

User · Answer

A solution using prototypes is only possible when your objects are alike:

function Cons(g) { this.good = g; }
Cons.prototype.bad = "something common";
var array = [new Cons("something 1"), new Cons("something 2"), …];

But then it's simple (and O(1)):

delete Cons.prototype.bad;

User · Answer

This question is a bit old now  but I would like to offer an alternative solution that doesn t mutate source data and requires minimal manual effort   function mapOut sourceObject  removeKeys           const sourceKeys   Object keys sourceObject     const returnKeys   sourceKeys filter k   gt   removeKeys includes k      let returnObject         returnKeys forEach k   gt        returnObject k    sourceObject k           return returnObject     const array         bad    something    good   something        bad   something    good   something        const newArray   array map obj   gt  mapOut obj     bad          It s still a little less than perfect  but maintains some level of immutability and has the flexibility to name multiple properties that you want to remove   Suggestions welcome

User · Answer

If you use underscore js   var strippedRows     map rows  function  row        return   omit row    bad    anotherbad

User · Answer

There are plenty of libraries out there  It all depends on how complicated your data structure is  e g  consider deeply nested keys  We like object-fields as it also works with deeply nested hierarchies  build for api fields parameter   Here is a simple code example  x000D   x000D     const objectFields   require  object-fields     const array       bad   something   good   something       bad   something   good   something        const retain   objectFields Retainer   good     retain array   console log array        gt      good   something       good   something      x000D   as-console-wrapper  max-height  100   important  top  0  x000D   lt script src  https   bundle run object-fields 2 0 19  gt  lt  script gt  x000D   x000D   x000D   Disclaimer  I m the author of object-fields

User · Answer

With ES6  you may deconstruct each object to create new one without named attributes   const newArray   array map   dropAttr1  dropAttr2     keepAttrs     gt  keepAttrs

User · Answer

The shortest way in ES6  array forEach e   gt   delete e someKey

User · Answer

I prefer to use map to delete the property and then return the new array item   array map function item         delete item bad       return item

User · Answer

I will suggest to use Object assign within a forEach   loop so that the objects are copied and does not affect the original array of objects  var res       array forEach function item         var tempItem   Object assign     item       delete tempItem bad       res push tempItem       console log res

User · Answer

You can follow this  more readable  not expectation raise due to key not found   data map  datum   gt                       return                            id  datum id                           title  datum login

User · Answer

For my opinion this is the simplest variant  array map   good     gt    good

User · Answer

i have tried with craeting a new object without deleting the coulmns in Vue js      let data  this selectedContactsDto        selectedContactsDto     object with list of array objects created in my     project     console log data            let newDataObj  data map   groupsList customFields firstname     item       item            console log  newDataObj  newDataObj

User · Answer

ES6  const newArray   array map   keepAttr1  keepAttr2     gt    keepAttr1  newPropName  keepAttr2

User · Answer

To remove some key value pair form object array uses Postgres SQL as database like this example  This is user function return user details object  we have to remove  quot api secret quot  key from rows       function getCurrentUser req  res  next       user function     var userId   res locals userId      console log userId      db runSQLWithParams  quot select   from users where id    1 quot    userId   function err  rows          if err           console log err                var responseObject              embedded  rows                responseObject  embedded 0  api secret   undefined          console log api            console log responseObject         res json responseObject               The above function return below object as JSON response before         quot  embedded quot                            quot id quot    quot 0123abd-345gfhgjf-dajd4456kkdj quot                quot secret key   quot secret quot                quot email quot    quot abcd email com quot                quot created quot    quot 2020-08-18T00 13 16 077Z quot                     After adding this line responseObject  embedded 0  api secret   undefined It gives below result as JSON response             quot  embedded quot                                    quot id quot    quot 0123abd-345gfhgjf-dajd4456kkdj quot                    quot email quot    quot abcd email com quot                    quot created quot    quot 2020-08-18T00 13 16 077Z quot

User · Answer

The only other ways are cosmetic and are in fact loops   For example    array forEach function v   delete v bad       Notes    if you want to be compatible with IE8  you d need a shim for forEach  As you mention prototype  prototype js also has a shim  delete is one of the worst  optimization killers   Using it often breaks the performances of your applications  You can t avoid it if you want to really remove a property but you often can either set the property to undefined or just build new objects without the property

User · Answer

x000D   x000D  var array      bad    something    good   something     bad   something    good   something     x000D  var results   array map function item   x000D    return  good   item  good    x000D      x000D  console log JSON stringify results    x000D   x000D   x000D

[javascript] Remove property for all objects in array

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