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

There is something really bizarre going on with this challenge. Fails in the challenge workspace, but on offline.

What is going on here? This exact code fails in the challenge workspace but is successful in my own offline workspace. I used a copy and paste to prove it.

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.dept === 'groceries')
  .reduce((total, item) => total + item.price, 0)
  .toFixed(2);
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.dept === 'groceries')
  .reduce((total, item) => total + item.price, 0)
  .toFixed(2);

console.log(groceryTotal);

2 Answers

Steven Parker
Steven Parker
231,248 Points

:warning: Be careful about testing a challenge in an external REPL. If is very easy to misinterpret the results.

The challenge is expecting the result to be a number, but by performing "toFixed" it is being converted to a string.

For best results, always do only what a challenge asks.

Seriously? I'll try it.

I'll be damned. You were right.