JavaScript Map Reference

JavaScript Map is a collection of elements where each element is stored as a key, value pair. Map objects can hold both objects and primitive values as either key or value. When we iterate over the map object it returns the key, and value pair in the same order as inserted.

Syntax:

Map.function()

Example: Below is an example of a Map.forEach() method.

Javascript

// Creating a map using Map object
let mp=new Map()

// Adding values to the map
mp.set("a",1);
mp.set("b",2);
mp.set("c",3);

// Logging map object to console
mp.forEach((values,keys)=>{
    console.log(values,keys)
})

Output:

1a
2b
3c

The complete list of JavaScript Map is listed below:

JavaScript Map Constructor: In JavaScript, a constructor gets called when an object is created using the new keyword.

Constructor	Description	Example
Map()	Create Map objects in JavaScript.	Try

JavaScript Map Properties: A JavaScript property is a member of an object that associates a key with a value.

• Instance Properties: An instance property is a property that has a new copy for every new instance of the class.

Instance Properties	Description	Example
constructor	It is used to return the constructor function of Map.	Try
size	Return the number of keys, and value pairs stored in a map.	Try

JavaScript Map Methods: JavaScript methods are actions that can be performed on objects.

• Instance Methods: If the method is called on the instance of a Map then it is called an instance method of Map.

Static Methods	Description	Example
clear( )	Removal of all the elements from a map and making it empty.	Try
delete()	Delete the specified element among all the elements which are present in the map.	Try
entries( )	Returning an iterator object which contains all the [key, value] pairs of each element of the map.	Try
forEach()	The map with the given function executes the given function over each key-value pair.	Try
get( )	Returning a specific element among all the elements which are present in a map.	Try
has( )	Check whether an element with a specified key exists in a map or not.	Try
keys()	The keys from a given map object return the iterator object of keys.	Try
set()	Add key-value pairs to a Map object.	Try
values()	Return a new Iterator object that contains the value of each element present in Map.	Try