How to delete an item by index from a state array in React

Question

I want to delete an object from an array of objects into another array in React, but I am a bit confused, so far I can push an object into the array. But abit confused how to delete it by index.

data

const addValues = [
  {
    "name": "New 1",
    "Value": [98,15,7,8]
  }, 
  {
    "name": "New 2",
    "Value": [7,18,9,40]
  },
  {
    "name": "New 3",
    "Value": [0,19,50,98]
  },
  {
    "name": "New 4",
    "Value": [56,89,34,20]
  },
]

const [value, setValue] = useState([]);

const handlePush = () => {
  setValue(oldArray => [...oldArray, newValue]);
};

 <div>{addValues?.map((inside, index) => {
    return (
      <React.Fragment key={index}>
         <p>{inside.name} <button onClick={() => setTags(oldArray => [...oldArray, addValue[index]])}>Add</button></p>
       </React.Fragment>
    )
  })}</div>

Can you show your code for deleting? – maxshuty Nov 08 '21 at 17:34 — maxshuty, Nov 08 '21 at 17:34

Alex Wayne · Answer 1 · 2021-11-08T18:48:17.197

6

If you want a subset of an immutable array, that's called a filter operation. And to remove an item by index, then you simply want filtering logic to filter out one specific index.

For example:

const handleRemove = (removeIndex) => {
  setValue(oldArray => {
    return oldArray.filter((value, i) => i !== removeIndex)
  })
}

edited Nov 08 '21 at 18:48

answered Nov 08 '21 at 17:37

Alex Wayne

178,991
47
309
337

This was also the answer i was writing ^^ – Stephan Hovius Nov 08 '21 at 17:38

score 2 · Answer 2 · answered Nov 08 '21 at 17:47

2

Can use filter to generated a new array without position you wanted to cut

Like this:

const filteredArray = items.filter((item, index) => index !== value);

answered Nov 08 '21 at 17:47

Gustavo Castro

21
1
6

score 0 · Answer 3 · answered Nov 08 '21 at 17:36

You can use the splice function to to this, given an array index:

const handleDelete = (arrayIndex) => {
  setValue(oldArray => oldArray.splice(arrayIndex,1));
};

Inside code

const addValues = [
  {
    "name": "New 1",
    "Value": [98,15,7,8]
  }, 
  {
    "name": "New 2",
    "Value": [7,18,9,40]
  },
  {
    "name": "New 3",
    "Value": [0,19,50,98]
  },
  {
    "name": "New 4",
    "Value": [56,89,34,20]
  },
]

const [value, setValue] = useState([]);

const handlePush = () => {
  setValue(oldArray => [...oldArray, newValue]);
};

const handleDelete = (arrayIndex) => {
  setValue(oldArray => oldArray.splice(arrayIndex,1));
};

 <div>{addValues?.map((inside, index) => {
    return (
      <React.Fragment key={index}>
         <p>{inside.name} <button onClick={() => setTags(oldArray => [...oldArray, addValue[index]])}>Add</button></p>
       </React.Fragment>
    )
  })}</div>

How to delete an item by index from a state array in React

3 Answers3

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