Object assign same key different value-CodePudding

function storage(data) {

  let object = {};

  data.forEach(line => {
    let [product, quantity] = line.split(' ');
    if (!object[product]) {
      object[product] = quantity;
    } else {
      let currentQuantity = Object.assign(object[product] = quantity); < -- - problem comes from here
      let newQuantity = Number(currentQuantity)   Number(quantity);
      Object.assign(product, newQuantity);
    }
  });

}
storage(['tomatoes 10', 'coffee 5', 'olives 100', 'coffee 40']);

Hello , I am new in the OOP and I want to combine different values from a key with same name.

output wanted ['tomatoes 10', 'coffee 45', 'olives 100']

CodePudding user response：

You shouldn't be using Object.assign(). That's for merging objects, not assigning a specific property. Just retrieve and assign object[product].

At the end you need to convert object back to an array of strings and return that.

function storage(data) {

  let object = {};

  data.forEach(line => {
    let [product, quantity] = line.split(' ');
    quantity = Number(quantity);
    if (!object[product]) {
      object[product] = quantity;
    } else {
      object[product]  = quantity;
    }
  });
  return Object.entries(object).map(([key, value]) => `${key} ${value}`);
}

console.log(storage(['tomatoes 10', 'coffee 5', 'olives 100', 'coffee 40']));

CodePudding user response：

You can simplify this a lot. There's no real benefit to be gained from using Object.assign. You probably also want to explicitly convert your quantities to numbers instead of using strings.

let displayStock = (data) => Object.entries(data).map( ([k, v]) => `${k} ${v}` )

function storage(data) {

  let object = {};

  data.forEach(line => {
    let [product, quantity] = line.split(' ');
    object[product] = (object[product] || 0)   Number(quantity)
  });
  return object;
}
let stock = storage(['tomatoes 10', 'coffee 5', 'olives 100', 'coffee 40']);

console.log(displayStock(stock))