var person = {"first_name": "Billy","last_name": "Johnson"}; delete person.last_name; //delete last_name property
var obj = {a: 5, b: 3}; delete obj["a"]; console.log(obj); // {b: 3}
delete object.keyname;
// Example 1 var key = "Cow"; delete thisIsObject[key]; // Example 2 delete thisIsObject["Cow"]; // Example 3 delete thisIsObject.Cow;