how to update properly an json´s object?

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I´m learning backend using node.js, so I´m developing a API RESTfull. I need to use PUT to update a object by id (the id as a params) in a json file. I´m using postaman to test.

This is my array:

[
  {
    "item": "phone",
    "price": 10000,
    "id": 1
  },
  {
    "item": "tv",
    "price": 20000,
    "id": 2
  },
  {
    "item": "nintendo",
    "price": 2500000,
    "id": 3
  },
  {
    "item": "ipad",
    "price": "500000",
    "id": 4
  }
]

For example I a have a local server http://127.0.0.1:8080/products/3 (the number 3 will be the item I wanna update changing the price or the name).

I started like this

app.put("/products/:id", (request, resolve) => {
  const id = Number(request.params.id);



})
node.js arrays json javascript
1 Answers

in a JSON file, you need to rewrite your data every time you update data

const data = require("./<fileName>.json"); // bring your json file
const fs = require("fs"); // fileModule to updata your json file

app.put("/products/:id", (request, resolve) => {
  const id = Number(request.params.id);

  let idx = data.findIndex(e=>e.id===id);// getting index of data by matching your id
  if(!idx){
    return resolve.json({message:"data not found"});
  }

  data[idx] = {} // your new data with id, you will get this data from request.body

  fs.writeFile("./<fileName>.json",JSON.stringify(data),(err)=>{  // writing updated data in your json fil
    if(err){
      return resolve.json({message:err}); // if you get ant error
    }
  });

  resolve.json(JSON.stringify(data)); // send response 
})

note:this is not the synchronous way of writing JavaScript. if you like my answer don't forget to upvote and follow.

user_119476310
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