D3.js Array.from() Method

With the help of Array.from() method, we can convert the map into an array by using this method.

Syntax :

Array.from( map )

Return value: It returns an array of different elements.

Note: To execute the below examples you have to install the d3 library by using the command prompt we have to execute the following command.

npm install d3

Example 1: In this example we can see that by using Array.from() method, we are able to get the array from map after conversion.

// Defining d3 contrib variable  
var d3 = require('d3');

data = [
  {name: "ABC",   amount: "34.0",   date: "11/12/2015"},
  {name: "DEF",  amount: "120.11", date: "11/12/2015"},
  {name: "MNO", amount: "12.01",  date: "01/04/2016"},
  {name: "XYZ", amount: "34.05",  date: "01/04/2016"}
]
var gfg = d3.group(data, d => d.name);

console.log(Array.from(gfg));

Output:

  [ [ 'ABC', [ [Object] ] ],
  [ 'DEF', [ [Object] ] ],
  [ 'MNO', [ [Object] ] ],
  [ 'XYZ', [ [Object] ] ] ]

Example 2:

// Defining d3 contrib variable  
var d3 = require('d3');

data = [
  {name: "ABC",   amount: "34.0",   date: "11/12/2019"},
  {name: "DEF",  amount: "120.11", date: "11/02/2020"},
  {name: "MNO", amount: "12.01",  date: "01/04/2020"},
  {name: "XYZ", amount: "34.05",  date: "03/04/2020"}
]

var gfg = d3.group(data, d => d.name, d => d.date);
console.log(Array.from(gfg));

Output:

[ [ 'ABC', Map { '11/12/2019' => [Array] } ],
  [ 'DEF', Map { '11/02/2020' => [Array] } ],
  [ 'MNO', Map { '01/04/2020' => [Array] } ],
  [ 'XYZ', Map { '03/04/2020' => [Array] } ] ]