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JavaScript JavaScript Array Iteration Methods Combining Array Methods Combining filter() and reduce()

Ioana Rusu
Ioana Rusu
9,599 Points

Help with this challenge

Hi,

I need help with this challenge as I cannot figure out how to select the right prices as dept of groceries. How should this code look ?

Got stuck with that.

Many thanks

app.js
const purchaseItems = [
    {
        name: 'apples',
        dept: 'groceries',
        price: 2.49
    },
    {
        name: 'bread',
        dept: 'groceries',
        price: 2.99
    },
    {
        name: 'batteries',
        dept: 'electronics',
        price: 5.80
    },
    {
        name: 'eggs',
        dept: 'groceries',
        price: 3.99
    },
    {
        name: 't-shirts',
        dept: 'apparel',
        price: 9.99
    }
];
let groceryTotal;

// groceryTotal should be: 9.47
// Write your code below

groceryTotal = purchaseItems
  .filter(item => item.price)
  .reduce((sum, item) => sum = item.price, 0);

1 Answer

Steven Parker
Steven Parker
220,682 Points

You're close, but your filter needs to select the *"items with a dept. of groceries". To do this, the argument needs to be a function that will return "true" when given an item in that department. Something like this:

  .filter(item => item.dept == 'groceries')

Then, the "reduce" function needs add to the sum instead of replacing it:

  .reduce((sum, item) => sum += item.price, 0);  // "+=" instead of just "="
Ioana Rusu
Ioana Rusu
9,599 Points

Oooh thanks again Steven. I have tried to select only the dept with groceries but not like that, I have tried the wrong way obviously !

I feel a little dumb asking for help almost every challenge :( Thanks again :)