remove a key in object JS code example

Example 1: remove key from object array javascript

array.forEach(function(v){ delete v.bad });

Example 2: 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