how to add and remove elements in array in javascript code example

Example 1: remove array elements javascript

let value = 3

let arr = [1, 2, 3, 4, 5, 3]

arr = arr.filter(item => item !== value)

console.log(arr)
// [ 1, 2, 4, 5 ]

Example 2: delete from array javascript

var arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0];var removed = arr.splice(2,2);/*removed === [3, 4]arr === [1, 2, 5, 6, 7, 8, 9, 0]*/

Example 3: javascript function to add or remove from array if

function removeItemOnce(arr, value) {
  var index = arr.indexOf(value);
  if (index > -1) {
    arr.splice(index, 1);
  }
  return arr;
}

function removeItemAll(arr, value) {
  var i = 0;
  while (i < arr.length) {
    if (arr[i] === value) {
      arr.splice(i, 1);
    } else {
      ++i;
    }
  }
  return arr;
}
//Usage
console.log(removeItemOnce([2,5,9,1,5,8,5], 5))
console.log(removeItemAll([2,5,9,1,5,8,5], 5))

Example 4: remove a value to an array of javascript

var data = [1, 2, 3];

// remove a specific value
// splice(starting index, how many values to remove);
data.splice(1, 1);
// data = [1, 3];

// remove last element
data.pop();
// data = [1, 2];