Today’s lecture will cover arrays and pseudo-arrays, as well as the main methods for working with them.

Arrays and pseudo-arrays are two different but similar data structures in JavaScript.

Arrays are a built-in type in JavaScript designed to store ordered collections of elements. They come with many useful methods for manipulating data.

Example of a simple array

let array = ['apple', 'banana', 'orange'];
console.log(array[0]); // 'apple'

Array features:

Array elements are indexed (starting from 0)
Arrays are dynamic: their length can change
Support methods for working with collections: push, pop, map, filter, reduce, etc.

Pseudo-arrays

Pseudo-arrays are objects that look like arrays but are not true arrays. They have numeric indexes and a length property but do not support array methods.

For example:

function showArguments() {
  console.log(arguments); // pseudo-array
}

Pseudo-array features:

Have numeric indices (e.g., 0, 1, 2)
Have a length property that indicates the number of elements
Do not support array methods (push, pop, map, etc.)