How to convert Map keys to an array in JavaScript ?
In this article, we are given a Map and the task is to get the keys of the map into an array using JavaScript. We can access the keys by using the Map keys() method.
We have a few methods to do this that are described below:
Approach 1: Using array.from() Method
- Declare a new map object
- Display the map content
- Use the keys() method on Map Object to get the keys of Map.
- Then use the array.from() method to convert a map object to an array.
Example: This example uses an array.from() method to get the keys of the Map in the array.
Javascript
let myMap = new Map().set( 'GFG' , 1).set( 'Geeks' , 2);
let array = Array.from(myMap.keys());
console.log(array.length);
|
- Declare a new map object
- Display the map content
- Use the [ …myMap.keys() ] method on Map Object to get the keys of Map as an array.
Example: This example uses the [ …Map.keys() ] method to get the keys of the Map in the array.
Javascript
let myMap = new Map().set( 'GFG' , 1).set( 'Geeks' , 2);
let array = [...myMap.keys()];
console.log(array.length);
|
Approach 3: Using for…of Loop Method
- Create an empty array
- By using the for…of Loop, we can iterate over the keys
- At each iteration, we can push the key into an array.
Example: This example shows the implementation of the above-explained approach.
Javascript
let myMap = new Map().set( 'GFG' , 1)
.set( 'Geeks' , 2).set( 'Geeksforgeeks' , 3);
let arr = [];
for (let key of myMap.keys()) {
arr.push(key);
}
console.log(arr);
|
Output
[ 'GFG', 'Geeks', 'Geeksforgeeks' ]
- Create an empty array
- Use Map.forEach() method for iterating over the loop
- then push the keys into an array
Example: This example shows the implementation of the above-explained approach.
Javascript
let myMap = new Map().set( 'GFG' , 1)
.set( 'Geeks' , 2)
.set( 'Geeksforgeeks' , 3);
let arr = [];
myMap.forEach((values, keys) => {
arr.push(keys);
});
console.log(arr);
|
Output
[ 'GFG', 'Geeks', 'Geeksforgeeks' ]
In this approach, we are using Lodash _.toArray() method that accept any value and convert it into an array.
Example: This example shows the implementation of the above-explained approach.
Javascript
const _ = require( "lodash" );
let myMap = new Map().set( 'GFG' , 1).set( 'Geeks' , 2);
let arr = _.toArray(myMap.keys());
console.log(arr.length);
|
Output:
2
Last Updated :
13 Dec, 2023
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