Collection in JavaScript

Arrays are ordered collections of values, and they are perhaps the most commonly used data structure in JavaScript. Elements in an array can be accessed by their index, and arrays can hold values of different data types.

let myArray = [1, 2, 3, 4, 5];
console.log(myArray[0]); // Accessing the first element

Objects in JavaScript are collections of key-value pairs. They are versatile and can be used to represent a wide range of data structures. Objects are often used for creating dictionaries, maps, and records.

let person = {
    name: "Maria",
    age: 28,
    city: "New York"
};
console.log(person.name); // Accessing a property

Keys are always strings (or Symbols, introduced in ES6). When you use non-string values as keys in an object, JavaScript implicitly converts them to strings.

Objects are generally used for a simple dictionary-like structure with string keys.