js remove 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: undefinedvar ourDog = {
  "name": "Camper",
  "legs": 4,
  "tails": 1,
  "friends": ["everything!"],
  "bark": "bow-wow"
};

delete ourDog.bark;delete object.keyname;var obj = {a: 5, b: 3};
delete obj["a"];
console.log(obj); // {b: 3}delete obj.firstname;// Example 1
var key = "Cow";
delete thisIsObject[key]; 

// Example 2
delete thisIsObject["Cow"];

// Example 3
delete thisIsObject.Cow;