Accessing sub-elements of an array (Javascript)

Question

I have an array called shopping list with elements containing the name of the product and its amount. Using the method .map I want to make a new array called product that only includes the product names from these elements. So that the new array would look like ['Milk', 'Coffee', 'Bananas', 'Bread'].

let shoppinglist = [ ['Milk', 1], ['Coffee', 2], ['Bananas'], ['Bread', 1] ];

const product = shoppinglist.map();

What do I put in after shoppinglist.map?

Answer 1

let shoppinglist = [ ['Milk', 1], ['Coffee', 2], ['Bananas'], ['Bread', 1] ];

by using map

let result = shoppinglist.map(a => a[0]);

by using Array.from

let result1 = Array.from(shoppinglist, a => a[0]);

Hope this helps you !

Answer 2

For the record, your shoppingList array should be an object : {milk: 1, coffe: 2...}.
In your case, the map function needs to returns the first element of each sub array. So something like that.

let shoppinglist = [ ['Milk', 1], ['Coffee', 2], ['Bananas'], ['Bread', 1] ];

console.log(shoppinglist.map((data) => data[0]));

Answer 3

const products = shoppinglist.map(item => item[0])

Answer 4

You can do it by returning the first element in the array using index 0.

let shoppinglist = [
  ['Milk', 1],
  ['Coffee', 2],
  ['Bananas'],
  ['Bread', 1]
];

const product = shoppinglist.map(item => item[0]);

console.log(product);