public/subjects/manipulate-keys/README.md

Manipulate Keys

Instructions

I do not want onions. I want oranges!!!

Create 3 functions that works like the .filter, .map and .reduce array method but for the keys of your grocery cart.

• filterKeys filters the name of the items you have.
• mapKeys changes the name of the items you have.
• reduceKeys reducing you grocery cart.

Examples

const nutrients = { carbohydrates: 12, protein: 20, fat: 5 }
console.log(filterKeys(nutrients, (key) => /protein/.test(key)))
// output :
// { protein: 20 }
console.log(mapKeys(nutrients, (k) => `-${k}`))
// output :
// { -carbohydrates: 12, -protein: 20, -fat: 5 }
console.log(reduceKeys(nutrients, (acc, cr) =>acc.concat(', ', cr)))
// output :
// carbohydrates, protein, fat

Notions

• devdocs.io/javascript/global_objects/array/filter
• devdocs.io/javascript/global_objects/array/map
• devdocs.io/javascript/global_objects/array/reduce
• devdocs.io/javascript/global_objects/object/entries
• devdocs.io/javascript/global_objects/object/fromentries

Code provided

all code provided will be added to your solution and doesn't need to be submited.

// small database with nutrition facts, per 100 grams
// 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: 12,  fiber: 0.2, fat: 0.1   },
}