How to Convert Between Data Structures in JavaScript
Objects, arrays, sets, maps, and more
JavaScript has several built-in data structures and in this article, we will look at how to convert between the most used of them: objects, arrays, sets, and maps.
Objects are collections of key-value pairs with a hidden property to their prototype.
Arrays are indexed collections of values.
Sets are collections of unique values.
Maps are collections of key-value pairs.
Objects and Maps
As we can see the definition of both objects and maps is pretty similar, they are both collections of key-value pairs so it is easier to convert between them.
Objects to Maps
Consider the following object storing translations.
const obj = {
"Hi": "Hola",
"Bye": "Adios"
}
We can convert it to a map using the Object.entries
helper and the Map
constructor.
The Object.entries
helper returns an array of [key, value]
pairs for the given object. It returns only the owned properties, not the ones inherited from the prototype.
console.log(Object.entries(obj))
//[
//["Hi", "Hola"],
//["Bye"…