Question 279375 in Javascript Question posted in
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Javascript – Function to change object properties conditionally

My task is to write a function that takes an object like the one below and deletes the "shelvesInCupboards" and "shelvesNotInCupboards" properties if they are present and adds a new property with their sum "totalShelves". I am not sure how to add my respective delete statements to get rid of the two mentioned properties without also altering my new "totalShelves" value.

Example object:

{
  shelvesInCupboards: 3,
  shelvesNotInCupboards: 2,
};

function sortTheKitchen(kitchen) {
    kitchen["totalShelves"] = 0;
    if (kitchen["shelvesInCupboards"] && kitchen["shelvesNotInCupboards"]) {
      totalShelves = kitchen["shelvesInCupboards"] + kitchen["shelvesNotInCupboards"]
    }
    if (kitchen["shelvesInCupboards"] && !kitchen["shelvesNotInCupboards"]) {
      totalShelves = kitchen["shelvesInCupboards"]
    }
    if (!kitchen["shelvesInCupboards"] && kitchen["shelvesNotInCupboards"]) {
      totalShelves = kitchen["shelvesNotInCupboards"]
    }
    return kitchen;
}
Tags:

2

Answers


  1. 0

    It quite simple, just delete the property after you get the value totalShelves. And you should use nullish operator combine with optional chaining to simplify your function.

    function sortTheKitchen(kitchen) {
  kitchen["totalShelves"] =
    (kitchen?.shelvesInCupboards ?? 0) + (kitchen?.shelvesNotInCupboards ?? 0);
  delete kitchen.shelvesInCupboards;
  delete kitchen.shelvesNotInCupboards;
  return kitchen;
}
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  2. 0

    You can use Array::reduce() to sum any number of object properties and delete them simultaneously:

    const kitchen = {shelvesInCupboards: 2, shelvesNotInCupboards: 3};
const kitchen2 = {shelvesInCupboards: 7};

function sortTheKitchen(kitchen) {
  kitchen.totalShelves = ['shelvesInCupboards', 'shelvesNotInCupboards']
    .reduce((r, name) => (r += kitchen[name] ?? 0, delete kitchen[name], r), 0);
  return kitchen;
}

console.log(sortTheKitchen(kitchen));
console.log(sortTheKitchen(kitchen2));
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