removing object from array with filters doesnt work in javascript-CodePudding

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' },
   ],

CodePudding user response：

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(...)

CodePudding user response：

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

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

CodePudding user response：

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

CodePudding user response：

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;
}