User Defined Object In JavaScript

In JavaScript, an object is a complex data type that allows you to store and organize data. Objects are collections of key-value pairs, where each key is a string (or a Symbol) and each value can be of any data type, including other objects. Objects in JavaScript are versatile and widely used in the language. Here's a basic overview of how objects work:

Creating an Object:

You can create an object using the curly braces {} notation.

let person = {
  name: "John Doe",
  age: 25,
  job: "Web Developer"
};

In this example, person is an object with three properties: name, age, and job.

Accessing Properties:

You can access the properties of an object using dot notation or square bracket notation.

console.log(person.name); // Output: John Doe
console.log(person['age']); // Output: 25

Adding and Modifying Properties:

You can add new properties or modify existing ones easily.

person.location = "Cityville";
person.age = 26;

console.log(person);
// Output: { name: 'John Doe', age: 26, job: 'Web Developer', location: 'Cityville' }

Nested Objects:

Objects can contain other objects as properties.

let car = {
  make: "Toyota",
  model: "Camry",
  year: 2022,
  owner: {
    name: "Alice",
    age: 30
  }
};

console.log(car.owner.name); // Output: Alice

Object Methods:

You can also include functions (methods) as properties of an object.

let calculator = {
  add: function(a, b) {
    return a + b;
  },
  subtract: function(a, b) {
    return a - b;
  }
};

console.log(calculator.add(5, 3)); // Output: 8

Iterating Over Object Properties:

You can use for...in loop to iterate over the properties of an object.

for (let key in person) {
  console.log(key + ": " + person[key]);
}

This will output each key-value pair in the person object.

Objects in JavaScript provide a flexible and powerful way to structure and manipulate data, making them a fundamental part of the language.