Multiplying 2 values in nested array then push to a new array - JavaScript Vue

Question

I have an array and I am trying to multiply two values qty and packageQuantity , creating a new array with the result set to the units key.

The trouble is I have a complex nested array and can't workout how to create a new array!

I have figured out how to do the multiplication, however I can't figure out how to push the values to a new array.

I am using Vue, and want to change the values live if possible.

How can I do the multiplication, creating a new array putting the result in the units key?

To clarify, I want to create a new array putting the new result in whilst adding the old values in too. See below.

Thanks so much in advance!

Here is my current array:

data: () => ({
sites: [

  {
    sku: "10001",
    values: [
      {
        variationName: { name: "Unpackaged", qty: 1 },
        units: '',
        packageQuantity: '2'
      }
    ]
  },
  {
    sku: "10002",
    values: [
      {
        variationName: { name: "2 Pack", qty: 2 },
        units: '',
        packageQuantity: '3'
      },
      {
        variationName: { name: "4 Pack", qty: 4 },
        units: '',
        packageQuantity: '1'
      }
    ]
  }
    ]
})

Here is what I want my output to be:

sites: [

  {
    sku: "10001",
    values: [
      {
        variationName: { name: "Unpackaged", qty: 1 },
        units: '2', // 1 * 2
        packageQuantity: '2'
      }
    ]
  },
  {
    sku: "10002",
    values: [
      {
        variationName: { name: "2 Pack", qty: 2 },
        units: '6', // 2 * 3
        packageQuantity: '3'
      },
      {
        variationName: { name: "4 Pack", qty: 4 },
        units: '4', // 1 * 4
        packageQuantity: '1'
      }
    ]
  }
    ]

Here is my calculation:

 sites.forEach(
  (innerArray) => innerArray.values.forEach(
   (item => console.log(item.variationName.qty * item.units))
  )
 )

Answer 1

           let newData=[]; 
            let sites = [

                {
                    sku: "10001",
                    values: [{
                        variationName: {
                            name: "Unpackaged",
                            qty: 1
                        },
                        units: '',
                        packageQuantity: '2'
                    }]
                },
                {
                    sku: "10002",
                    values: [{
                            variationName: {
                                name: "2 Pack",
                                qty: 2
                            },
                            units: '',
                            packageQuantity: '3'
                        },
                        {
                            variationName: {
                                name: "4 Pack",
                                qty: 4
                            },
                            units: '',
                            packageQuantity: '1'
                        }
                    ]
                }
            ]
            for (let i = 0; i < sites.length; i++) {
                let iData = sites[i].values;
                for (let j = 0; j < iData.length; j++) {
                    iData[j].units = parseInt(iData[j].packageQuantity) * parseInt(iData[j].variationName.qty);
                }

            }
             newData.push(sites);

Output

    newData: [
            {
                sku: "10001",
                values: [{
                    variationName: {
                        name: "Unpackaged",
                        qty: 1
                    },
                    units: 2, 
                    packageQuantity: '2'
                }]
            },
            {
                sku: "10002",
                values: [{
                        variationName: {
                            name: "2 Pack",
                            qty: 2
                        },
                        units: 6,
                        packageQuantity: '3'
                    },
                    {
                        variationName: {
                            name: "4 Pack",
                            qty: 4
                        },
                        units: 4, 
                        packageQuantity: '1'
                    }
                ]
            }
        ]

Answer 2

You can take what you've already done and assign it to item.units . But you have to remember to convert the values to integers before the multiplication. You'll also have to convert the result back to a string if you need it as a string. Here's how you would do it if all values were numbers:

 sites.forEach(
    (innerArray) => innerArray.values.forEach(item => { 
       item.units = item.variationName.qty * item.units; 
    })
 )

It might be worth noting that what you've called innerArray isn't really an array and actually an object so you might want to name it better for clarity's sake.

Answer 3

Here is what you could do:

const datum = {
  sites: [

    {
      sku: "10001",
      values: [
        {
          variationName: { name: "Unpackaged", qty: 1 },
          units: 5,
          packageQuantity: ""
        }
      ]
    },
    {
      sku: "10002",
      values: [
        {
          variationName: { name: "2 Pack", qty: 2 },
          units: 3,
        },
        {
          variationName: { name: "4 Pack", qty: 4 },
          units: 6,
          packageQuantity: ""
        }
      ]
    }
      ]
  };

const qtyCalculated = datum && datum.sites && datum.sites.reduce((acc, site) => {
  if (!acc["sku"]) {
    acc["sku"] = [];
  }
  acc["sku"].push(site.sku);
  if (!acc["qty"]) {
    acc["qty"] = [];
  }
  acc["qty"].push(...site.values && site.values.reduce((valueAcc, valueItem) => {
    valueAcc.push(valueItem.variationName.qty * parseInt(valueItem.units, 10));
    return valueAcc;
  }, []));
  return acc;
}, []);

console.log(qtyCalculated);

You can add the name and have the quantity calculated individually for every value item too. I have declared the units a number in the datum. If you are using a string, use the parseInt as above.