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

Jonathan Grieve
MOD
Jonathan Grieve
Treehouse Moderator 91,253 Points
Posted by Jonathan Grieve
Jonathan Grieve
Treehouse Moderator 91,253 Points

Problem with the reducer method for getting total of groceries

I'm pretty sure the problem is with the filter method but all I'm getting from the code challenge is "Unexpected token ." So I think I'm close but I'm out of ideas on this one :)

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(department => purchaseItems.department == "groceries")
.reduce(sum, department) => sum + purchaseItems.price, 0
.toFixed(2);

1 Answer

Matt Brock
Matt Brock
28,330 Points
Matt Brock
Matt Brock
28,330 Points

You were missing the parentheses around the guts of the .reduce() function and your arguments were just a little off:

groceryTotal = purchaseItems

.filter(item => item.dept == 'groceries')
.reduce((sum, item) => sum + item.price, 0)
.toFixed(2);
Jonathan Grieve
Jonathan Grieve
Treehouse Moderator 91,253 Points
Jonathan Grieve
Jonathan Grieve
Treehouse Moderator 91,253 Points

Having tested this code on a local file I believe that code should be passing.

I'm getting an error Both the `reduce` and `filter` methods have not been called yet.

Joel Kraft would you be able to check it out and confirm? :)

Matt Brock
Matt Brock
28,330 Points

For whatever reason, removing the .toFixed() method passed the challenge:

groceryTotal = purchaseItems
.filter(item => item.dept == 'groceries')
.reduce((sum, item) => sum + item.price, 0);