SakoMe/data.csv

## data.csv

          
            Mark Williams
            waffle iron
            80
            2

            
              Mark Williams
              blender
              200
              1

            
              Mark Williams
              knife
              10
              4

            
              Nikita Smith
              waffle iron
              80
              1

            
              Nikita Smith
              knife
              10
              2

            
              Nikita Smith
              pot
              20
              3

## super_reduce.js
const fs = require('fs');

let output = fs.readFileSync('data.csv', 'utf8')
	.trim()
	.split('\n')
	.map(line => line.split(','))
	.reduce((customers, line) => {
		customers[line[0]] = customers[line[0]] || []
		customers[line[0]].push({
			name: line[1],
			price: line[2],
			quantity: line[3]
		})
		return customers
	}, {})


console.log('output', JSON.stringify(output, null, 2));
Mark Williams	waffle iron	80	2
Mark Williams	blender	200	1
Mark Williams	knife	10	4
Nikita Smith	waffle iron	80	1
Nikita Smith	knife	10	2
Nikita Smith	pot	20	3
	const fs = require('fs');

	let output = fs.readFileSync('data.csv', 'utf8')
	.trim()
	.split('\n')
	.map(line => line.split(','))
	.reduce((customers, line) => {
	customers[line[0]] = customers[line[0]] \|\| []
	customers[line[0]].push({
	name: line[1],
	price: line[2],
	quantity: line[3]
	})
	return customers
	}, {})


	console.log('output', JSON.stringify(output, null, 2));