JS tips: searching the index of an element and delete or replace it

Published Sep 30, 2017Last updated Oct 06, 2017
JS tips: searching the index of an element and delete or replace it

The challenge

How do you search the index of an element in an array and then delete or replace it?

Solution

  1. Use array.findIndex or array.map to get the index.
  2. Use array.splice to replace or to delete.

The Code

// Existing array.
var array = [
  { email: 'fooz@bar.co',
    id: '0c2df03e-b12c-48a8-b52b-82d55425e283',
    name: 'rob' },
  { email: 'fooz@bar.co',
    id: '1d763175-5369-4d25-8608-d6d04f630a60',
    name: 'jane' },
  { email: 'fooz@bar.co',
    id: '16253b3e-1020-4431-91f3-d206072e142f',
    name: 'mark' }
]

// New element.
var newItem = {
  email: 'fooz@bar.co',
  id: '1d763175-5369-4d25-8608-d6d04f630a60',
  name: 'janie'
}

// Id to look up for.
var id = newItem.id

// Find index of an item.
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/findIndex
// var index = array.findIndex(function(item) {return item.id === id})
// Or:
var index = array.findIndex(item => item.id === id)

// Replace the item by index.
array.splice(index, 1, newItem)

// To check.
console.log(array) // 'jane' is now 'janie'.

// Another method to search for the index.
var index = array.map(function(el) {
  return el.id
}).indexOf(id)

// Delete  the item by index.
array.splice(index, 1)

// To check.
console.log(array) // 'janie' is now gone.

Suggestions

Let me know what you think and what would be your solutions. Anything suggestions, please leave a comment below. Hope this helps.

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