How to replace an item in an array with JavaScript?

Question

Each item of this array is some number.

var items = Array(523,3452,334,31, ...5346);

How do I replace some number in with array with a new on

Answer 1

The immutable way to replace the element in the list using ES6 spread operators and .slice method.

const arr = ['fir', 'next', 'third'], item = 'next'

const nextArr = [
  ...arr.slice(0, arr.indexOf(item)), 
  'second',
  ...arr.slice(arr.indexOf(item) + 1)
]

Verify that works

console.log(arr)     // [ 'fir', 'next', 'third' ]
console.log(nextArr) // ['fir', 'second', 'third']