How to sort a map in JavaScript ?

In JavaScript, a map can be sorted in multiple ways. Here are some methods to sort a map in JavaScript:

Method 1: Using the Array.sort() method 1. Convert the map to an array of key-value pairs using the Map.entries() method. 2. Sort the array using the Array.sort() method and a custom sorting function that compares the values of the key-value pairs. 3. Convert the sorted array back to a map using the Map() constructor.

Example:

let myMap = new Map();
myMap.set("John", 25);
myMap.set("Mary", 30);
myMap.set("Bob", 20);

let sortedMap = new Map([...myMap.entries()].sort((a, b) => a[1] - b[1]));

console.log(sortedMap); // Output: Map { 'Bob' => 20, 'John' => 25, 'Mary' => 30 }

Method 2: Using the lodash library 1. Install the lodash library using npm or yarn. 2. Import the sortBy() function from the lodash library. 3. Pass the map and a custom function that returns the value of each key-value pair to the sortBy() function.

Example:

const _ = require('lodash');

let myMap = new Map();
myMap.set("John", 25);
myMap.set("Mary", 30);
myMap.set("Bob", 20);

let sortedMap = new Map(_.sortBy(Array.from(myMap), [(o) => o[1]]));

console.log(sortedMap); // Output: Map { 'Bob' => 20, 'John' => 25, 'Mary' => 30 }

Method 3: Using the Map() constructor and the spread operator 1. Convert the map to an array of key-value pairs using the Map.entries() method. 2. Sort the array using the Array.sort() method and a custom sorting function that compares the values of the key-value pairs. 3. Create a new map using the Map() constructor and the spread operator to add the sorted key-value pairs to the new map.

Example:

let myMap = new Map();
myMap.set("John", 25);
myMap.set("Mary", 30);
myMap.set("Bob", 20);

let sortedArray = [...myMap].sort((a, b) => a[1] - b[1]);
let sortedMap = new Map(sortedArray);

console.log(sortedMap); // Output: Map { 'Bob' => 20, 'John' => 25, 'Mary' => 30 }