Remove Last Item from Array

Remove last item from array

Use splice(startPosition, deleteCount)

array.splice(-1)

var array = ['abc','def','ghi','123'];
var removed = array.splice(-1);  //last item
console.log( 'array:', array );
console.log( 'removed:', removed );

Delete last item from array with useState

There are 3 possible solutions to your problem.

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Solution 1:
Slice the array from the first element to the -1 (1 before the last) element.

setTodos(todos.slice(0, -1)));

Or

setTodos((previousArr) => (previousArr.slice(0, -1)));

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Solution 2:
Create a copy array and splice it with the value of -1. Then set the array from the first element to the -1 element.

const copyArr = [...todos];
copyArr.splice(-1);
setTodos(copyArr);

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Solution 3:
Create a copy list with the ..., pop the copy and set the new value of the array to the copy.

const copyArr = [...todos];
copyArr.pop();
setTodos(copyArr);

How to remove last item in Javascript array?

To eliminate the last element of the array, use Array.pop() and to join array elements into a string, separated with spaces, you must pass a space to .join().

The commas are showing up because you are logging an array and the commas are auto inserted to separate array items for you, the reader - they are not actual parts of the array. But, if you want the words as a string, just passing a space to the .join() method gives you the output you want.

var inputVal = document.getElementById("txtWords");
inputVal.addEventListener("blur", function(){
  tags = inputVal.value.split(' ');  // create tags array
  tags.pop();  // remove last word
  tags = tags.join(" ");  // array to string separated by spaces
  console.log(tags);  });

Type some words in the box and then hit TAB: <input type="text" id="txtWords">

Delete last object from the array of objects.

You could just splice out the last element in the array:

obj.Results.splice(-1);

var obj = {  Results: [{    id: 1,       name: "Rick",    Value: "34343"  }, {    id:2,    name: 'david',    Value: "2332",  }, {    id: 3,    name: 'Rio',    Value: "2333"  }]};
obj.Results.splice(-1);console.log(obj);

Removing an item from an array of items only removes the last item

Because you're using index as key. The key will help react know which one should be updated. So you need to provide a unique value for each component.

FYI: https://reactjs.org/docs/lists-and-keys.html

The quick fix for your example:

let id = 0 // Introduce id variable

export default function App() {

Increase Id each time you add new item:

  const addNewForm = () => {
    id++;
    setForms([
      ...forms,
      {
        id,
        valuesOfForm: { firstname: "", lastname: "" }
      }
    ]);
  };

Change the key to id:

<SomeForm
  value={form.valuesOfForm}
  key={form.id}
  index={index}

Everything will work after this

Remove last element from array if it matches a particular condition

If it's the last element you're after then you don't need the loop at all, just check if the array is empty or not and access the last element directly:

function dedupeLast(a, target) {
   if(a.length && a[a.length - 1] === target){
      a.pop();
   }
}

It reads: if a is not empty (a.length != 0) and the last element a[a.length - 1] === target then, remove the last element using pop.

How to not delete last element in array (Dart language)

Simply check the length of the list before removing the element. If it reaches 1 item, it stops deleting.

Column( 
 children: [
  TextButton(child: const Text ('Remove Me'), 
     onPressed: () { 
     if(_listTexts.length > 1) setState((){ 
     _listTexts.removeLast();
     });
   }),
 ])

How to remove last element from every row of a matrix in javascript

The first argument to .map is the item you're iterating over, not the index.

Since each item here is an array, you can either .pop the array (which will mutate the existing array), or .slice the array (which will not mutate the existing array).

var matrixWithExtraInfo = [    [1,2,3,4,"dog"],    [5,6,7,8,"dog"],    [9,10,11,12,"dog"],    [13,14,15,16,"dog"],    [17,18,19,20,"dog"]];
var conciseMatrix = [    [1,2,3,4],    [5,6,7,8],    [9,10,11,12],    [13,14,15,16],    [17,18,19,20]]
var conciseMatrix = matrixWithExtraInfo.map((arr) => {  arr.pop();  return arr;});console.log(matrixWithExtraInfo);console.log(conciseMatrix);

Delete 2nd to last item array

You can use splice method instead. This is an example:

let arr = [1,2,3];arr.splice(-2,1);console.log(arr);

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