re: How to clone a portion of an object using the power of IIFE, arrow functions, destructuring assignment and property shorthands. VIEW POST

FULL DISCUSSION
 

You could also write

const { lastName: _, ...luca } = person
 

Does lastName value get assigned to const _? I take it the _ is a convention for unused variables, seen it used before for arguments that are not referenced (I think)

 

Yup, it's mostly an unwritten rule adopted as a convention for variables that must be there but aren't going to be referenced anywhere. Similarly if you want to use .map() but only need the index, not the element itself for some weird reason:

const newArr = arr.map((_, idx) => { /* do something only with idx */ });
 

Excellent solution: i love the spread syntax. But i think in this case it's gonna work only for a few and well known properties to exclude from the wanted output (luca). What if the original object has hundreds of them?

Anyways, there are plenty of solutions to this problem. One for all, if you'd like to rely on some dependency: lodash.

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