getting minimum value of a field in an array javascript-CodePudding

I have an array of items in which i want to extract only the cheapest version of that product . e.g i have two iphones XS but i want to only extract the cheaper one and add all the cheapest items into another array . Below is items .

  const [items,setItems] = useState([
    {"itemid":"001" , "Product":"Iphone XS MAX PRO 512GB","Price" : 1200},
    {"itemid":"002" , "Product":"Samsung Galaxy S20 128GB","Price" : 700},
    {"itemid":"003" , "Product":"Huwaei x8 ","Price" : 600},
    {"itemid":"004" , "Product":"OPPO","Price" : 400},
    {"itemid":"005" , "Product":"Nokia","Price" : 200},
    {"itemid":"006" , "Product":"OPPO","Price" : 500},  
    {"itemid":"007" , "Product":"Iphone XS MAX PRO 512GB","Price" : 900},
  ])

As you can see there are two Oppo items and two iphone items . I need to get only the cheapest version out of both of them and for the rest of the other items also.How would i do this ?

Any suggestions will be appreciated

CodePudding user response：

Filter by Product name using RegExp.prototype.test()
Reduce the filtered results by Price property using Array.prototype.reduce()

const data = [
  {"itemid":"001" , "Product":"Iphone XS MAX PRO 512GB","Price" : 1200},
  {"itemid":"002" , "Product":"Samsung Galaxy S20 128GB","Price" : 700},
  {"itemid":"003" , "Product":"Huwaei x8 ","Price" : 600},
  {"itemid":"004" , "Product":"OPPO","Price" : 400},
  {"itemid":"005" , "Product":"Nokia","Price" : 200},
  {"itemid":"006" , "Product":"OPPO","Price" : 500},  
  {"itemid":"007" , "Product":"Iphone XS MAX PRO 512GB","Price" : 900},
];

const filtered = data.filter(item => /\biphone xs\b/i.test(item.Product));
const result = filtered.reduce((prev, curr) => prev.Price < curr.Price ? prev : curr);

console.log(result);

To create a reusable function that returns the cheapest item (by Price) by providing an array to search and a product name:

// Utility function to escape regex sensitive characters
const regEscape = (str) => str.replace(/[/\-\\^$* ?.()|[\]{}]/g, '\\$&');

// Get cheapest product by Price given a Product name from array of products:
const getCheapest = (products, name) => {
  const filtered = products.filter(item => new RegExp(`\\b${regEscape(name)}\\b`, "i").test(item.Product));
  const result = filtered.reduce((prev, curr) => prev.Price < curr.Price ? prev : curr);
  return result;
};

const data = [
  {"itemid":"001" , "Product":"Iphone XS MAX PRO 512GB","Price" : 1200},
  {"itemid":"002" , "Product":"Samsung Galaxy S20 128GB","Price" : 700},
  {"itemid":"003" , "Product":"Huwaei x8 ","Price" : 600},
  {"itemid":"004" , "Product":"OPPO","Price" : 400},
  {"itemid":"005" , "Product":"Nokia","Price" : 200},
  {"itemid":"006" , "Product":"OPPO","Price" : 500},  
  {"itemid":"007" , "Product":"Iphone XS MAX PRO 512GB","Price" : 900},
];

console.log(getCheapest(data, "iphone xs"));

CodePudding user response：

I don't know anything about react or what useState() does, but if you are looking for a way to get the "cheapest" choice for each product then the following might be helpful:

const cheapest=Object.values([
{"itemid":"001" , "Product":"Iphone XS MAX PRO 512GB","Price" : 1200},
{"itemid":"002" , "Product":"Samsung Galaxy S20 128GB","Price" : 700},
{"itemid":"003" , "Product":"Huwaei x8 ","Price" : 600},
{"itemid":"004" , "Product":"OPPO","Price" : 400},
{"itemid":"005" , "Product":"Nokia","Price" : 200},
{"itemid":"006" , "Product":"OPPO","Price" : 500},  
{"itemid":"007" , "Product":"Iphone XS MAX PRO 512GB","Price" : 900},
  ].reduce((a,c)=>{
   a[c.Product]??=c;
   if (c.Price<a[c.Product].Price) 
    a[c.Product]=c;
   return a;}
   ,{}));

console.log(JSON.stringify(cheapest));

CodePudding user response：

Sort by price in ascending order, create a new array without already-existing items.

[...items]
.sort((a, b) => (a.price > b.price ? 1 : -1))
.reduce((acc, x) =>
acc.filter(y => y.Product == x.Product).length ? acc : [...acc, x], []);