How to add default value and alias using ES6 de-structuring?

Question

I have a specific use case where I want to do a nested de-structuring and assign an alias (rename it to another variable name, say aliasD) as well as a default value to a property. E.g.

const a = { b: { c: [{ d: 'value' }] } };

and while destructuring I only need d but with an alias aliasD and a default value defaultVal. SO I tried below, but I am not sure what I am missing

const a = { b: { c: [{ d: 'value' }] } };
const { b: { c: [first: { d: aliasD = defaultVal }] } } = a;

console.log(aliasD);

But this doesn't work

Answer 1

The problem here is for destructuring the array, the correct syntax to get the first value of the array would be:

[varName] = yourArray

Applying that to your example:

const { b: { c: [{ d: aliasD = 'test' }] } } = a;

You can try it out with Babel REPL