Question 245622 in Javascript Question posted in
A very good W3school tutorial can be found here.

Javascript – Removing one object from an array by its id, node.js

    const arr=[]

    let id=0
    app.post('/book',(req,res)=>{
      payload={body: req.body,id: id+1}
      id=id+1
      arr.push(payload)
      console.log("arr",arr);
      return res.send("success")
    })

`this is how I created the push function in an array with default id

i try to delete element from this array by its id using pop or using some loop`

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2

Answers


  1. 0

    first of all you need to convert the id into number then use filter to delete the required element like so:

    const deleteId = parseInt(req.body.id);

arr = arr.filter(item => item.id !== deleteId);

console.log("arr", arr);
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  2. 0

    This is a tested snippet which works successfully:

        const arr=[]

    let id=0
    while (id < 10) {
      payload={body: "some text " + id,id: id+1}
      id=id+1
      arr.push(payload)
    }
    
    let toRemove = arr.map((item, index) => ((item.id == 3) ? index : false)).filter(item => (item !== false));
    
    if (toRemove.length) {
        for (let indexToRemove = toRemove[0]; indexToRemove < arr.length - 1; indexToRemove++) {
            arr[indexToRemove] = arr[indexToRemove + 1];
        }
        
        arr.pop();
    }
    
    console.log(arr);

    I’m:

    • mapping the items of an array to their index if the id matches and false otherwise (assuming that an id is unique)
    • then filter the result by the items not being false, getting the index to remove
    • then check whether the id was found
    • and if so, loop the array starting from that index to the end
    • and copy the next item into the current one
    • except for the last element which is popped

    Tested with an id of 3, you can use the value you want instead.

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