Objects and Arrays in JavaScript

  In JavaScript, objects and arrays are fundamental data structures that allow us to store and organize information efficiently.

What are Objects in JavaScript?

  Objects in JavaScript are collections of key-value pairs. Each pair consists of a key (or property) and an associated value, which can be any data type, including other objects or arrays.

• Creating objects: You can create an object using curly braces ``.
• Accessing properties: Object properties can be accessed using dot notation or bracket notation.
• Example of an object:

  const person = `name: "John", age: 30, city: "Madrid"`;

What are Arrays in JavaScript?

  Arrays are data structures that allow us to store multiple values in a single variable. The values within an array are ordered and can be accessed by their index.

• Creating arrays: An array is created using square brackets `[]`.
• Accessing elements: Array elements are accessed via their index, starting from 0.
• Example of an array:

  const numbers = [10, 20, 30, 40];

Useful Methods for Objects and Arrays

  Both objects and arrays have built-in methods that facilitate their manipulation. Some useful methods include:

• For Objects:
  • Object.keys(obj) - Gets the keys of an object.
  • Object.values(obj) - Gets the values of an object.
  • Object.entries(obj) - Gets an array with the entries (key-value pairs) of an object.
• For Arrays:
  • push() - Adds an element to the end of the array.
  • pop() - Removes the last element of an array.
  • shift() - Removes the first element of an array.
  • unshift() - Adds an element to the beginning of the array.

  Both objects and arrays are essential tools in JavaScript and are used in a wide variety of contexts to organize, manipulate, and store data.