The mapToGroups() method is used to iterate through the collection elements and passes each value of collection into the given callback function.
Syntax:
collect(array).mapToGroups(callback)
Parameters: The collect() method takes one argument that is converted into the collection and then mapToGroups() method is applied on it. The mapToGroups() method holds the callback function as a parameter.
Return Value: This method returns the collection elements according to given callback.
Below example illustrate the mapToGroups() method in collect.js:
Example 1:
Javascript
const collect = require( 'collect.js' ); let obj = [{ name: 'Ashok' , score: 75 }, { name: 'Rakesh' , score: 86 }, { name: 'Rajesh' , score: 56 }, { name: 'Rakesh' , score: 98 }]; const collection = collect(obj); const sequence = collection.mapToGroups( (element) => [element.name, element.score]) console.log(sequence.all()); |
Output:
{ Ashok: [ 75 ], Rakesh: [ 86, 98 ], Rajesh: [ 56 ] }
Example 2:
Javascript
const collect = require( 'collect.js' ); let obj = [ { name: 'Rahul' , dob: '25-10-96' , }, { name: 'Aditya' , dob: '25-10-96' , }, { name: 'Abhishek' , dob: '16-08-94' , }, { name: 'Rahul' , dob: '25-10-96' , }, ]; const collection = collect(obj); const sequence = collection.mapToGroups( (element) => [element.dob, element.name]) console.log(sequence.all()); |
Output:
{ '25-10-96': [ 'Rahul', 'Aditya', 'Rahul' ], '16-08-94': [ 'Abhishek' ] }