Object destructuring with dynamic keys

This technique is useful when you don’t know the property name ahead of time and still want to destructure it cleanly. I often use this for deleting keys from an object. Useful in state reducers.

const keyToExtract = "email";
const user = {
  name: "Sen",
  email: "sen@senhongo.com",
  role: "guy",
};

const { [keyToExtract]: extractedValue, ...rest } = user;

console.log(extractedValue); // sen@senhongo.com
console.log(reset); // { name: "Sen", role: "guy" }

• keyToExtract is a dynamic variable that holds the name of the key we want to pull out.
• The property with the key email is extracted into extractedValue.
• The rest of the object goes into rest.