How to in React return array without duplicates or sum duplicate objects

Question

Please help me to find a solution and a bit with my code refactoring.

I just want to put some objects from one array to a new and it will be like a product cart. That's why I don't want to see any duplicates but just: product - quantity in the modal window. I've got two arrays:

state = {
  existData: [
    {
      productName: "CoolProductName 1",
      count: 0,
      image: "src.jpeg",
      author: "Name Surname",
      date: "21.02.2020",
      id: 1,
    },
    {
      productName: `CoolProductName 2"`,
      count: 0,
      image: "src.png",
      author: "Name Surname",
      date: "21.02.2020",
      id: 2,
    },
  ],
  addedToCart: [],
};

So, the function is:

added = (id) => {
  //get product Id from other component

  this.setState(({ addedToCart, existData }) => {
    let newObj = existData.filter((el) => el.id === id); // there is I get product selected by user from array of all products

    return {
      addedToCart: [...addedToCart, ...newObj],
    };
  });
};

With my little knowledge I thought to do something like:

let newObj = existData
  .filter((el) => el.id === id)
  .map((el) => {
    if (el.count >= 0) {
      el.count++;
    }
    return { ...el };
  });

yes it returns value with the count++ but in addedToCart array I've got duplicates objects with different counts. I see two ways:

remove duplicates in addedToCart array after add an object to the cart and increase count then just show something like {addedToCart.prductName} - {addedToCart.count} in the cart.
count duplicate objects and remove count field.

What is the better way and suitable code? Thank you

There is solution suitable to me: ` added = (id) => { this.setState (( { addedToCart, dataList } )=>{ // filter return an Array but // find return an element, what we are looking for by id const newItem = dataList.find(el=>el.id===id); const mainArr = [...addedToCart ]; // if there is no in shopping cart if(mainArr.find(el=>el.id===id) == undefined){ newItem.count = 1; mainArr.push(newItem); } // if exist then count ++ else{ mainArr.find(el=>el.id===id).count++; } return{ addedToCart: mainArr } })}; ` — Sergey V.
– Sergey V., Commented Apr 22, 2021 at 14:49

Rafael Buzatto de Campos · Accepted Answer · 2021-03-09 22:18:45Z

I would keep aside count from product Details. Also, addedToCart would be an object, where its key are the ids with and the value is the count;

new state format:

state = {
  existData: [
    {
      productName: "CoolProductName 1",
      image: "src.jpeg",
      author: "Name Surname",
      date: "21.02.2020",
      id: 1,
    },
    {
      productName: `CoolProductName 2"`,
      image: "src.png",
      author: "Name Surname",
      date: "21.02.2020",
      id: 2,
    },
  ],
  addedToCart: {}, //store id and count here
};

this way added would check for id keys to update its count:

added = (id) => {
  //get product Id from other component
  this.setState(({ addedToCart }) => {
    const count = typeof addedToCart[id] === "undefined" ? 1 : ++addedToCart[id];
    return { addedToCart: { ...addedToCart, [id]: count } };
  });
};

This way you avoid any object duplication, and segregates cart's items from product details. If you need to access a product's count you can check this.state.addedToCart[id] if it exists and return its count accordingly.

basic implementation example:

Rodrigo Pissinate · Accepted Answer · 2021-03-09 19:57:26Z

0

According to React docs, setState should be like: setState(updater, [callback]),

If I'm not mistaken, your are passing a callback in the place of the updater.

It should look like this.setState({ state: 'something' }, () => { console.log('something') })

React does not accept calling new functions with pre existents Components names.

answered Mar 9, 2021 at 19:57

Rodrigo Pissinate

331 silver badge6 bronze badges

Collectives™ on Stack Overflow

How to in React return array without duplicates or sum duplicate objects

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related