let user = {     // an object
  name: "John",  // by key "name" store value "John"
  age: 30        // by key "age" store value 30
};

function makeUser(name, age) {
  return {
    name: name,
    age: age,
    // ...other properties
  };
}

let user = makeUser("John", 30);
alert(user.name); // John

let user = {
  name: "John",
  age: 30
};

user.sayHi = function() {
  alert("Hello!");
};

user.sayHi(); // Hello!

let user = {
  name: "John",
  age: 30,

  sayHi() {
    // "this" is the "current object"
    alert(this.name);
  }

};

user.sayHi(); // John

let user = {
  name: "John",
  age: 30,

  sayHi() {
    alert(user.name); // "user" instead of "this"
  }

};

function sayHi() {
  alert( this.name );
}

function BigUser() {

  this.name = "John";

  return { name: "Godzilla" };  // <-- returns this object
}

alert( new BigUser().name );  // Godzilla, got that object

function BigUser(){
  this.name = "Fotima"
  
  return {name: "Godzila"};
}
alert(new BigUser().name );
console.log(new BigUser())

function BigUser(){
  this.name = "Fotima"
  
  return {name: "Godzila"};
}
alert(new BigUser().name );
console.log(new BigUser().name)

let id = Symbol("id");
alert(id.description);
console.log(Symbol())

{name: "John", age: 30}.

let john = {
  name: "John",
  sayHi: function() {
    alert("Hi buddy!");
  }
};

john.sayHi(); // Hi buddy!      

One of the best things about objects is that we can store a function as one of its properties.