The get() method of Map instances returns the value corresponding to the key in this Map, or undefined if there is none. Object values are returned as the same reference that was originally stored, not as a copy, so mutations to the returned object will be reflected anywhere that reference is held, including inside the Map.

Try it

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

console.log(map.get("bar"));
// Expected output: "foo"

console.log(map.get("baz"));
// Expected output: undefined

Syntax

get(key)

Parameters

key

The key of the value to return from the Map object. Object keys are compared by reference, not by value.

Return value

The value associated with the specified key in the Map object. If the key can't be found, undefined is returned.

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"]

Specifications

Browser compatibility

See also

• Map
• Map.prototype.delete()
• Map.prototype.set()
• Map.prototype.has()