batches.js

/**
It accepts two objects as arguments: the first object is the recipe
for the food, while the second object is the available ingredients.
Each ingredient's value is a number representing how many units there are.

`batches(recipe, available)`
*/

function batches(recipe, available) {
  const recipeArray = Object.keys(recipe);
  const possibleServings = [];
  for (const ingredient of recipeArray) {
    possibleServings.push(available[ingredient] / recipe[ingredient] || 0);
  }

  return Math.floor(Math.min(...possibleServings));
}

// const batches = (recipe, available) =>
//   Math.floor(
//     Math.min(
//       ...Object.keys(recipe).map(
//         ingredient => available[ingredient] / recipe[ingredient] || 0
//       )
//     )
//   );
// 0 batches can be made
console.log(
  batches(
    { milk: 100, butter: 50, flour: 5 },
    { milk: 132, butter: 48, flour: 51 }
  )
);

console.log(
  batches(
    { milk: 100, flour: 4, sugar: 10, butter: 5 },
    { milk: 1288, flour: 9, sugar: 95 }
  )
);

// 1 batch can be made
console.log(
  batches(
    { milk: 100, butter: 50, cheese: 10 },
    { milk: 198, butter: 52, cheese: 10 }
  )
);

// 2 batches can be made
console.log(
  batches(
    { milk: 2, sugar: 40, butter: 20 },
    { milk: 5, sugar: 120, butter: 500 }
  )
);