null checking of array using question mark break

Question

I have this array of object

const a = {a:[{b:[{prop: 10}]}]}

to access the value of 10 I do

a.a[0].b[0].prop // 10

I use this fallback, make sure things doesn't break but it didn't work?

a?.a[0]?.b[0]?.prop

, I can use something like lodash's get or check using the old method but how to use the question mark syntax?

Answer 1

Optional chaining should be written as below

a?.[0]?.b?.[0].prop