Reassigning from JS Object A property value to another

Question

I'm trying to assign prices to my items from a JSON A to JSON B, managed to get the prices and reassign it to the property but not to the whole object.

here's a snippet of my code, which gets the prices from the first Object and reassigning it to TotalOrignialValue however how can I push it back to the newJson object?

Is there a more pleasing way of achieving this?

 // Code goes here var items = { "TransactionLine": [ { "Product": { "Id": null, "Codes": [ "1112" ], "Sku": null }, "TotalValue": 2.35, }, { "Product": { "Id": null, "Codes": [ "1113" ], "Sku": null }, "TotalValue": 2.15, } ], "CustomData": {} }; var itemPrice = []; for (var i = 0; i < items.TransactionLine.length; i++) { var el = items.TransactionLine[i]; itemPrice.push(el.TotalValue); console.log(el.TotalValue); } var newJson = { "OrderLines": [ { "Product": { "Id": 9, "Codes": [ "1113" ], "Sku": "CS1113" }, "TotalOriginalValue": 0, // asign the price here }, { "Product": { "Id": 21, "Codes": [ "1112" ], "Sku": "CS1112" }, "TotalOriginalValue": 0, // asign the price here } ] }; var newPrice = []; for (var x = 0; x < newJson.OrderLines.length; x++) { var xd = newJson.OrderLines[x].TotalOriginalValue; xd = itemPrice[x]; newjson = { "TotalOriginalValue": xd }; newPrice.push(newjson); } console.log('newJSON >> ', newPrice); 

Answer 1

it looks like your only connection from JSON A to JSON B is the codes array on the items.

You could loop over entries in JSON a, find the corresponding item in JSON B by checking the codes values, and assign the values directly on JSON B entries

 var items = { "TransactionLine": [ { "Product": { "Id": null, "Codes": [ "1112" ], "Sku": null }, "TotalValue": 2.35, }, { "Product": { "Id": null, "Codes": [ "1113" ], "Sku": null }, "TotalValue": 2.15, } ], "CustomData": {} }; var newJson = { "OrderLines": [ { "Product": { "Id": 9, "Codes": [ "1113" ], "Sku": "CS1113" }, "TotalOriginalValue": 0, // asign the price here }, { "Product": { "Id": 21, "Codes": [ "1112" ], "Sku": "CS1112" }, "TotalOriginalValue": 0, // asign the price here } ] }; items.TransactionLine.forEach(item=>{ var match = newJson.OrderLines.find(entry=>entry.Product.Codes[0] === item.Product.Codes[0]); if (!match) { return; } match.TotalOriginalValue = item.TotalValue; }); console.log(newJson); 

This will also cut out the use of the array and a loop through the items JSON. On a list of 2 its not so bad, but add a few hundred/thousand and it will become noticeable.

Answer 2

Using Lodash makes your life so much easier that does what you need using lodash there is probably an even more succinct way of doing it with it.

var items = {
    "TransactionLine": [
      {
        "Product": {
          "Id": null,
          "Codes": [
            "1112"
          ],
          "Sku": null
        },
        "TotalValue": 2.35,
      },
      {
        "Product": {
          "Id": null,
          "Codes": [
            "1113"
          ],
          "Sku": null
        },
        "TotalValue": 2.15,
      }
    ],
    "CustomData": {}
  };



  var newJson = {
    "OrderLines": [
          {
            "Product": {
              "Id": 9,
              "Codes": [
                "1113"
              ],
              "Sku": "CS1113"
            },
            "TotalOriginalValue": 0, // asign the price here
          },
          {
            "Product": {
              "Id": 21,
              "Codes": [
                "1112"
              ],
              "Sku": "CS1112"
            },
            "TotalOriginalValue": 0, // asign the price here
          }
        ]
  };

var test = _.map(items.TransactionLine, (item,index) => {
return _.set(newJson.OrderLines[index], 'TotalOriginalValue', item.TotalValue)
})

console.log(test)

https://jsfiddle.net/k6vdyhx7/124/

Answer 3

Iterate over OrderLines key value, which is an array, then replace every TotalOriginalValue value with responding value from the items.TransactionLine array.

 var items = {TransactionLine:[{Product:{Id:null,Codes:["1112"],Sku:null},TotalValue:2.35},{Product:{Id:null,Codes:["1113"],Sku:null},TotalValue:2.15}],CustomData:{}}, newJson = {OrderLines:[{Product:{Id:9,Codes:["1113"],Sku:"CS1113"},TotalOriginalValue:0},{Product:{Id:21,Codes:["1112"],Sku:"CS1112"},TotalOriginalValue:0}]}; newJson.OrderLines.forEach((v,i) => v.TotalOriginalValue = items.TransactionLine[i].TotalValue); console.log(newJson);