removing object from array with filters doesnt work in javascript

Question

I am trying to remove an object from an array but it I dont know what I am doing wrong.

I have this array declared:

listA: [
       { title: 'Food', value: 'Patato' },
       { title: 'Drink', value: 'Cola' },
       { title: 'Desert', value: 'Cheesecake' },
       ],

I am trying to remove the object where its value is 'Cola', what I have tried is this:

  this.listA.filter(x => x.value !== 'Cola');

And it returns me the same list

I want to return this:

 listA: [
   { title: 'Food', value: 'Patato' },
   { title: 'Desert', value: 'Cheesecake' },
   ],

Note that the filter for !== is different than !=. This can catch you out if you think you're comparing numbers but you're actually comparing a number and a string representation of a number! — James McCormack
– James McCormack, Commented Aug 23, 2024 at 12:01

mhodges · Accepted Answer · 2022-01-12 20:40:01Z

3

Your code should be filtering just fine, I think the issue here is that filter does not modify the original array, it returns a new array with the filtered results. If you want it to overwrite the original array, you'll need to say this.listA = this.listA.filter(...)

answered Jan 12, 2022 at 20:40

mhodges

11.2k2 gold badges32 silver badges48 bronze badges

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

1 Comment

Nina Over a year ago

Thank you, it works!!

Tasos Tsournos · Accepted Answer · 2022-01-12 20:38:26Z

1

const listA = [
  { title: "Food", value: "Patato" },
  { title: "Drink", value: "Cola" },
  { title: "Desert", value: "Cheesecake" },
];

const result = listA.filter((obj) => obj.value !== 'Cola');

answered Jan 12, 2022 at 20:38

Tasos Tsournos

3933 silver badges10 bronze badges

Comments

Jjagwe Dennis · Accepted Answer · 2022-01-12 20:39:59Z

1

Looks like you need to do something like

this.listA = this.listA.filter(x => x.value !== 'Cola')

The filter method is immutable hence the original array isn't changed

answered Jan 12, 2022 at 20:39

Jjagwe Dennis

1,87312 silver badges13 bronze badges

Comments

score 0 · Accepted Answer · 2022-01-12 20:57:36Z

0

As a complement to https://stackoverflow.com/a/70688107/6316468, here is what filter does under the hood (the original array this remains untouched):

var xs = [1, 2, 3, 4];
var ys = filter.call(
  xs, x => x % 2
);
console.log(
  "xs = [", xs.join(), "]"
);
console.log(
  "ys = [", ys.join(), "]"
);

function filter(predicate) {
  var xs = []; // new array
  for (let x in this) {
    if (predicate(x)) {
      xs.push(x);
    }
  }
  return xs;
}

edited Jan 12, 2022 at 20:57

answered Jan 12, 2022 at 20:51

user6316468

Collectives™ on Stack Overflow

removing object from array with filters doesnt work in javascript

4 Answers 4

1 Comment

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

1 Comment

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related