delete

const employee = {
  firstName: "Maria",
  lastName: "Sanchez",
};

console.log(employee.firstName);
// : "Maria"

delete employee.firstName;

console.log(employee.firstName);
// : undefined

delete object.property
delete object[property]

delete identifier;
delete object.#privateProperty;

delete console.log(1);
// 1  true 

// empCount 
// var 
var empCount = 43;

//  EmployeeDetails 
// "var" 
EmployeeDetails = {
  name: "xyz",
  age: 5,
  designation: "Developer",
};

// delete 
delete EmployeeDetails.name; // true 

//  delete  "true" 
delete EmployeeDetails.salary; // true 

// EmployeeDetails 
delete EmployeeDetails; // true 

//  empCount  var 
delete empCount; // false 

// delete 
delete Math.PI; // false 

function f() {
  var z = 44;

  // delete 
  delete z; // false 
}

function Foo() {
  this.bar = 10;
}

Foo.prototype.bar = 42;

const foo = new Foo();

// foo.bar 
// 
console.log(foo.bar); // 10

// foo 
// 
delete foo.bar; // true 

// foo.bar 
// 
console.log(foo.bar); // 42

// 
delete Foo.prototype.bar; // true 

// "bar"  Foo 
// 
console.log(foo.bar); // undefined

const trees = ["redwood", "bay", "cedar", "oak", "maple"];
delete trees[3];
console.log(3 in trees); // false

const trees = ["redwood", "bay", "cedar", "oak", "maple"];
trees[3] = undefined;
console.log(3 in trees); // true

const trees = ["redwood", "bay", "cedar", "oak", "maple"];
trees.splice(3, 1);
console.log(trees); // ["redwood", "bay", "cedar", "maple"]

const Employee = {};
Object.defineProperty(Employee, "name", { configurable: false });

console.log(delete Employee.name); // false 

// "nameOther"  var 
// 
var nameOther = "XYZ";

// 
Object.getOwnPropertyDescriptor(globalThis, "nameOther");
// {
//   value: "XYZ",
//   writable: true,
//   enumerable: true,
//   configurable: false
// }

delete globalThis.nameOther; // false 

globalThis.globalVar = 1;
console.log(globalVar); // 1
// `delete globalVar` 
delete globalThis.globalVar;
console.log(globalVar); // ReferenceError: globalVar is not defined