how to delete element from array

Question

I'm facing an issue to fix a bug.

I'm getting data from dataBase. the data ( object ) contains an array of names. I have useState hook that contains an array of objects. The value is names. I want to delete every object from the useState hook that much the name from the array fetched for dataBase.

Exp:

response.data.players = ["player1", "player2"]

const [names, setNames] = useState([
{value: "player1", label: "player1"},
{value: "player3", label: "player3"},
{value: "player2", label: "player2"},
{value: "player5", label: "player5"},
])

I want the names become like this:

[
{value: "player3", label: "player3"},
{value: "player5", label: "player5"},
]

with minimum time complexity ( I'm already using .map to serve other hook with the names, if I can use it it will be perfect for the time complexity )

Thank you

a bug or code optimization with min time complexity? what are the contents of .map? — Raptor
– Raptor, Commented Sep 15, 2021 at 2:10
response.data.condidates.map((elem, index) => { dataCondidate.push(elem) }) this one is serving another functionality — SEMER BEN SALEM
– SEMER BEN SALEM, Commented Sep 15, 2021 at 2:12

DecPK · Accepted Answer · 2021-09-15 02:35:00Z

1

That just sounds like a filter to me. Can't you just do something like this:

setNames(names.filter(name => !response.data.players.includes(name.label)))

For reference, here's that working without React:

const names = [{
    value: "player1",
    label: "player1"
  },
  {
    value: "player3",
    label: "player3"
  },
  {
    value: "player2",
    label: "player2"
  },
  {
    value: "player5",
    label: "player5"
  },
];

const response = {
  data: {
    players: ["player1", "player2"],
  },
};


const filteredNames = names.filter(name => !response.data.players.includes(name.label))

console.log(filteredNames);

edited Sep 15, 2021 at 2:35

DecPK

25.4k6 gold badges32 silver badges46 bronze badges

answered Sep 15, 2021 at 2:18

djs

4,0753 gold badges18 silver badges28 bronze badges

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

1 Comment

DecPK Over a year ago

It is always a great option to make the code runnable.

DecPK · Accepted Answer · 2021-09-15 02:32:47Z

1

You can efficiently achieve the result using Set and filter

const names = [
  { value: "player1", label: "player1" },
  { value: "player3", label: "player3" },
  { value: "player2", label: "player2" },
  { value: "player5", label: "player5" },
];

const players = ["player1", "player2"];

const set = new Set(players);
const result = names.filter(({ label }) => !set.has(label));
console.log(result);

answered Sep 15, 2021 at 2:32

DecPK

25.4k6 gold badges32 silver badges46 bronze badges

2 Comments

SEMER BEN SALEM Over a year ago

I didn't use set before, it's new for me. Ill read about it. Also i tried the code and it worked. I really appreciate your help:)

DecPK Over a year ago

It's added in ES6 and If you have a very large dataset in players then It is better to use the has method of Set to check for existence rather than includes of an array. has is optimized for checking existence. If you have a small data set then you can use either one. Happy learning 😊

Collectives™ on Stack Overflow

how to delete element from array

2 Answers 2

1 Comment

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related