best way to delete key value in js object code example

Example 1: javascript delete key from object

let person = {
  firstname: 'John',
  lastname: 'Doe'
}

console.log(person.firstname);
// expected output: "John"

delete person.firstname;

console.log(person.firstname);
// expected output: undefined

Example 2: how to remove key value pair from object in javascript

delete object.keyname;