Discussion on: Optional Chaining may be coming to JavaScript

[Jean-Jacques Dubray]

You can achieve a similar result with simple functions like:

const O = (val, value = {}) => val && (typeof val === 'object') ? val : value
const A = (val, value = []) => val && Array.isArray(val) ? val : value
const S = (val, value = '') => val && (typeof val === 'string') ? val : value
const N = (val, value = 0) => isNaN(val) ? value : val
const NZ = (val, value = 1) => val === 0 || isNaN(val) ? value === 0 ? 1 : value : val
const F = (f, f0 = () => null) => f ? f : f0

const a = {}

console.log(O(a.b))             // {}
console.log(A(O(a.b).c))        // []
console.log(NZ(a))              // 1 (non-zero number)
console.log(N(a))               // 0 (number)
console.log(S(a, 'hello'))      // hello
console.log(F(a.b)(123))        // null

It's not much more overhead and it works today.