javascript - Replace element at specific position in an array without mutating it

Question

How can the following operation be done without mutating the array:

let array = ['item1'];
console.log(array); // ['item1']
array[2] = 'item2'; // array is mutated
console.log(array); // ['item1', undefined, 'item2']

In the above code, array variable is mutated. How can I perform the same operation without mutating the array?

question from:https://stackoverflow.com/questions/38060705/replace-element-at-specific-position-in-an-array-without-mutating-it

Answer 1

You can use Object.assign:

Object.assign([], array, {2: newItem});