public/subjects/manipulate-values

Manipulate Values

Instructions

Let's buy groceries.

You have a grocery cart with some items you need. The item's name is the key, and the value will represent nutrition facts per 100 grams.

Create 3 functions that work like the .filter, .map and .reduce array methods, for the values in your grocery cart object. You can see their function names and how they work in the examples.

Examples

const nutrients = { carbohydrates: 12, protein: 20, fat: 5 }

console.log(filterValues(nutrients, (nutrient) => nutrient <= 12))
// output: { carbohydrates: 12, fat: 5 }

console.log(mapValues(nutrients, (v) => v+1))
// output: { carbohydrates: 13, protein: 21, fat: 6 }

console.log(reduceValues(nutrients, (acc, cr) => acc + cr))
// output: 37

You will have a small database to help you with the groceries.

Code provided

The provided code will be added to your solution, and does not need to be submitted.

// small database with nutrition facts, per 100 grams
// In this exercise this is used for testing purposes only
// prettier-ignore
const nutritionDB = {
    tomato:  { calories: 18,  protein: 0.9,   carbs: 3.9,   sugar: 2.6, fiber: 1.2, fat: 0.2   },
    vinegar: { calories: 20,  protein: 0.04,  carbs: 0.6,   sugar: 0.4, fiber: 0,   fat: 0     },
    oil:     { calories: 48,  protein: 0,     carbs: 0,     sugar: 123, fiber: 0,   fat: 151   },
    onion:   { calories: 0,   protein: 1,     carbs: 9,     sugar: 0,   fiber: 0,   fat: 0     },
    garlic:  { calories: 149, protein: 6.4,   carbs: 33,    sugar: 1,   fiber: 2.1, fat: 0.5   },
    paprika: { calories: 282, protein: 14.14, carbs: 53.99, sugar: 1,   fiber: 0,   fat: 12.89 },
    sugar:   { calories: 387, protein: 0,     carbs: 100,   sugar: 100, fiber: 0,   fat: 0     },
    orange:  { calories: 49,  protein: 0.9,   carbs: 13,    sugar: 9,   fiber: 0.2, fat: 0.1   },
  }

Notions

• filter
• map
• reduce
• entries
• fromEntries