change one value in array of objects

Question

I have array with objects users:

let state = {
  users: [
    {id: 1, name: 'Igor',  selected: false},
    {id: 2, name: 'Anton', selected: false},
    {id: 3, name: 'Vasya', selected: false},
    {id: 4, name: 'Pete',  selected: false},
    {id: 5, name: 'Dan',   selected: false}
  ], ....

And a function that works with this object:

export function selectUser(userId) {
  if (state.users.find(item => item.id == userId).selected == false) {
    /* some code */

    //[needed] Code to update the user property selected to true

  } else {
    /* some other code */

    //[needed] Code to update the user property selected to true
  }
  emitChange();
}

How to do that, without overwriting the whole array, strangely can't think of anything

Please label with the language being used. It looks like JavaScript, but then again Pepsi looks like Coke but I would never want to drink Pepsi. — Tim Biegeleisen
– Tim Biegeleisen, Commented Dec 28, 2015 at 8:32
when you say change you mean you want to replace or modify existing object ? — Bek
– Bek, Commented Dec 28, 2015 at 8:49
@ikffs Your code makes no sense as the true case is the same as the false case according to the comments. Please rework your question. — ViRuSTriNiTy
– ViRuSTriNiTy, Commented Dec 28, 2015 at 8:51

Bek · Accepted Answer · 2015-12-28 09:03:29Z

1

if you want to toggle property then

export function selectUser(userId) {
  var user = state.users.find(user => user.id == userId);
  var isSelected = user.selected; 
  // state.users.forEach(user => user.selected = false ); deselect others 
  user.selected = !isSelected;
  emitChange();
}

answered Dec 28, 2015 at 9:03

Bek

3,2051 gold badge19 silver badges28 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Quantumplate · Accepted Answer · 2015-12-28 08:53:12Z

1

The find() method returns the object you want to update. So call that first and assign it to a variable, then test it exists and if so then work with it.

export function selectUser(userId) {
  var user = state.users.find(item => item.id == userId);

  if (user != 'undefined'){
    if (user.selected == false) {
      /* some code */

      user.name = 'New Name';
      // etc

    } else {
      /* some other code */
    }
  }

  emitChange();
}

answered Dec 28, 2015 at 8:53

Quantumplate

1,1048 silver badges17 bronze badges

Comments

ViRuSTriNiTy · Accepted Answer · 2015-12-28 09:05:21Z

1

According to the comments in the true and false case this should work:

export function selectUser(userId) {
  var user = state.users.find(item => item.id == userId);
  if (user && user.selected == false) {
    user.selected = true;
  } else {
    /* some other code */
  }
  emitChange();
}

edited Dec 28, 2015 at 9:05

answered Dec 28, 2015 at 8:56

ViRuSTriNiTy

5,2052 gold badges35 silver badges63 bronze badges

3 Comments

Igor Kim Over a year ago

find() returns new object, so you are modifying "user" in your code not original object

ViRuSTriNiTy Over a year ago

@ikffs Where did you get that information? According to the specs Array.find() returns the object itself, not a copy or something like that. I've also tested it and it works.

Igor Kim Over a year ago

jeez buddy, you are a lifesaver, sorry for long response, I don't know why but I really thought that find returns some other object, silly me! thanks

Collectives™ on Stack Overflow

change one value in array of objects

3 Answers 3

Comments

Comments

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related