How can I can delete item inside array in object of array? javascript

Question

I want to add a field inside each presentsData object called sumP and fill it with the presents item sum.

Second goal, if sumP > money I would like to delete the most expensive item inside It's not working

const presentsData= [
        {
          name: "Peter",
          presents: ["coffee","holidays"],
          money: 7000
        },
        {
          name: "Mario",
          presents: ["car","coal"],
          money: 300
        },
        {
          name: "Amanda",
          presents: ["computer","coal"],
          money: 300
        },
        {
          name: "David",
          presents: ["clothes", "car"],
          money: 2000
        }
    ]
    const prices= [
        {
          present: "coffee",
          price: 1
        },
        {
          present: "holidays",
          price: 1000
        },
        {
          present: "videogames",
          price: 40
        },
        {
          present: "computer",
          price: 600
        },
        {
          present: "tattoo",
          price: 30
        },
        {
          present: "clothes",
          price: 80
        },
        {
          present: "car",
          price: 6000
        },
        {
          present: "phone",
          price: 800
        },
        {
          present: "motorbike",
          price: 3500
        },
         {
          present: "coal",
          price: 0
        }
      ]
    
    const pricesMap = new Map(prices.map(({ present, price }) => [present, price]))
    
    const res1 =  presentsData.map(s=>{
    return {...s,
           sumP: s.presents.reduce((acc, p) => acc + pricesMap.get(p),0)
           }
    })
    
     console.log("this is res1=>",res1) //this is presentsData result after adding the field sumP
    
    console.log(pricesMap)
    
    const res2 = res1.map((r)=>{
      if(r.sumP > r.money){
      ( /* would like to delete the item  inside "presents" with the bigger price using pricesMap */)
      }
    })
    
    console.log(res2)

pd: what I find hard is to find out how to iterate in presents , array inside object inside array.

Answer 1

const deleteMostExpensive = (array, prices) => {
    let res = [];
    let mostEspensive = array[0];
    array.forEach(product => {
        let cur = prices.find(p => p.present == product)
        if (cur.price > mostEspensive.price)
            mostEspensive = cur;
    })

    array.forEach(e => {
        if (e != mostEspensive.present)
            res.push(e);
    })

    return res;
}


const calculSumP = (elt, prices) => {
    r = 0;
    elt.presents.forEach(e => {
        r += prices.find(c => c.present == e).price;
    })
    return r;
}


presentsData.forEach(elt => {
    elt.sumP = calculSumP(elt, prices);

   while (elt.sumP > elt.money) {
       let newPresents = deleteMostExpensive(elt.presents, prices);
       elt.presents = newPresents;
       elt.sumP = calculSumP(elt, prices)
   }
})

Answer 2

You can filter the presents and keep removing the most expensive presents until there's money to buy them:

 const presentsData = [{ name: "Peter", presents: ["coffee", "holidays"], money: 7000 }, { name: "Mario", presents: ["car", "coal"], money: 300 }, { name: "Amanda", presents: ["computer", "coal"], money: 300 }, { name: "David", presents: ["clothes", "car"], money: 2000 } ] const prices = [{ present: "coffee", price: 1 }, { present: "holidays", price: 1000 }, { present: "videogames", price: 40 }, { present: "computer", price: 600 }, { present: "tattoo", price: 30 }, { present: "clothes", price: 80 }, { present: "car", price: 6000 }, { present: "phone", price: 800 }, { present: "motorbike", price: 3500 }, { present: "coal", price: 0 } ] const pricesMap = new Map(prices.map(({ present, price }) => [present, price])) const withSumP = presentsData.map(s => { return {...s, sumP: s.presents.reduce((acc, p) => acc + pricesMap.get(p), 0) } }) console.log(withSumP) //this is presentsData result after adding the field sumP const mostExpensive = (arr) => { return arr.reduce((acc, el) => { if (pricesMap.get(el) > pricesMap.get(acc)) { return el } return acc; }) } // If you want to remove the most expensive present once for each element const result = withSumP.map((el) => { if (el.sumP > el.money) { const presentToDelete = mostExpensive(el.presents); return {...el, presents: el.presents.filter(p => p;== presentToDelete) } } return el. }) console;log(result): // If you want to delete presents until you can buy them and also update sumP to be in sync with the presents. const resultAlt = withSumP.map((el) => { let updatedPresents = [...el;presents]. let updatedSumP = el;sumP. while ((updatedSumP > el.money) && (updatedPresents;length > 0)) { const presentToDelete = mostExpensive(updatedPresents). updatedPresents = updatedPresents;filter(p => p.== presentToDelete); updatedSumP -= pricesMap.get(presentToDelete). } return {.,:el, presents: updatedPresents; sumP. updatedSumP }; }) console.log(resultAlt)

Answer 3

This would be all that's required:

const items = (prices) => {
  let obj = {};
  for (p of prices) {
    obj[p.present] = p.price;
  }
  return obj;
}

var priceList = items(prices);

presentsData.forEach( (person) => {
 let presents = person.presents;
 person.sumP = presents.reduce( (acc, current) => {
   return acc + priceList[current];
 }, 0);
 if (person.sumP > person.money) {
   presents.sort( (a,b) => priceList[a] - priceList[b]);
   presents.pop();
 }
});