JavaScript Objects

Definition: An object groups related data as key:value pairs. It is ideal for describing one "thing" with several properties — a user, a product, a car.

let person = {
  name: "Sam",
  age: 25,
  city: "London"
};
console.log(person);

Example 1 — reading properties

console.log(person.name);    // Sam (dot notation)
console.log(person["age"]);  // 25 (bracket notation)

Example 2 — changing and adding

person.age = 26;               // change
person.email = "sam@mail.com"; // add new
console.log(person);

Example 3 — methods (functions inside objects)

Inside a method, this refers to the object itself:

let user = {
  name: "Sam",
  greet: function() {
    console.log("Hi, I am " + this.name);
  }
};
user.greet();

Example 4 — array of objects (very common)

let people = [
  {name: "Sam", age: 25},
  {name: "Alex", age: 30}
];
console.log(people[1].name); // Alex

💡 Arrays vs objects: arrays hold values by position; objects hold values by name. Combine them to model real data.