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Map.prototype.get()

The get() method of Map instances returns a specified element from this map. If the value that is associated to the provided key is an object, then you will get a reference to that object and any change made to that object will effectively modify it inside the Map object.

Try it

Syntax

get(key)

Parameters

key: The key of the element to return from the Map object.

Return value

The element associated with the specified key, or undefined if the key can't be found in the Map object.

Examples

Using get()

const myMap = new Map();
myMap.set("bar", "foo");

console.log(myMap.get("bar")); // Returns "foo"
console.log(myMap.get("baz")); // Returns undefined

Using get() to retrieve a reference to an object

const arr = [];
const myMap = new Map();
myMap.set("bar", arr);

myMap.get("bar").push("foo");

console.log(arr); // ["foo"]
console.log(myMap.get("bar")); // ["foo"]

Note that the map holding a reference to the original object effectively means the object cannot be garbage-collected, which may lead to unexpected memory issues. If you want the object stored in the map to have the same lifespan as the original one, consider using a WeakMap.

Specifications

Specification
ECMAScript Language Specification # sec-map.prototype.get

Browser compatibility

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet	WebView Android	Deno	Node.js
`get`	38	12	13	25	8	38	14	25	8	3.0	38	1.0	0.12.0