Question 259839 in Javascript Question posted in
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How to update the array object value on the basis of index in Javascript ES6

I wants to update the array object value on the basis of the index in Javascript ES6 with the following json data and javascript code. I want to update the description.

 const products = [
  {
    "id": 1,
    "description": "Milk Powder",
    "qty": 2,
    "unitprice": 200,
    "totalamount": 400
},
{
    "id": 2,
    "description": "Air Conditioner",
    "qty": 5,
    "unitprice": 500,
    "totalamount": 2500
},
{
    "id": 3,
    "description": "RC Cars",
    "qty": 30,
    "unitprice": 800,
    "totalamount": 24000
},
{
    "id": 4,
    "description": "Down Coat",
    "qty": 2,
    "unitprice": 300,
    "totalamount": 600
}
]

Javascript Code

const handleProductName = (e, index) =>{
   const item = [...products,[index].description=e.target.value]
 }
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2

Answers


  1. 0

    As discussed in the comments, it appears as though you want to avoid updating the original array of objects (ie: treat it as immutable/read only). Since products is an array and not an object it doesn’t make much sense to spread it into an object like you’re currently doing. I would suggest however using a newer method (introduced after ES6, in ES2023), called .with() which allows you to update an index from your array but produces a new array, without touching the original:

    const updatedProducts = products.with(index, {...products[index], description: e.target.description});

    If you can’t support with yet, it is easy enough to polyfill if needed as well.

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  2. 0

    I doubt you already have the index and you actually mean id. But if you did, this could be a solution using slice:

     const products = [
  {
    "id": 1,
    "description": "Milk Powder",
    "qty": 2,
    "unitprice": 200,
    "totalamount": 400
},
{
    "id": 2,
    "description": "Air Conditioner",
    "qty": 5,
    "unitprice": 500,
    "totalamount": 2500
},
{
    "id": 3,
    "description": "RC Cars",
    "qty": 30,
    "unitprice": 800,
    "totalamount": 24000
},
{
    "id": 4,
    "description": "Down Coat",
    "qty": 2,
    "unitprice": 300,
    "totalamount": 600
}
]

// Get item by index (this is not the same as ID!!)
// As said in the comments, it's hard to know what decides this index you talk about
let index = 1

// Get the correct item, which is not hard because apparantely we have the index
let product = products[index]

// Replace the description of this item
product.description = 'This is changed'

// Replace new item with old item
products.splice(index,index,product)

// Show new products list
console.log(products)
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