Addition keys in JSON

Question

I need to make addition using NodeJS in an array JSON and then return the altered JSON like this, I need also check if key exist or not to avoid exceptions:

JSON:

{
    "cmd": [
        {
            "sales": [
                {
                    "qte1": "2",
                    "qte2": "3", 
                    "someString": "test 
                },
                {
                    "qte1": "66",
                    "someAttribute": "test " 
                },
                {
                    "qte2": "77",
                    "toto": "tata"
                }
            ]
        }
    ]
}

target JSON:

{
    "cmd": [
        {
            "sales": [
                {
                    "qte1": "2",
                    "qte2": "3",
                    "somme": "5"
                },
                {
                    "qte1": "66",
                    "somme": "66"

                },
                {
                    "qte2": "77",
                    "somme": "77"
                }
            ]
        }
    ]
}

I need to add the two key qte1 et qte2 would you have any propositions ?

Best regards

In JavaScript you can transform json to objects with `JSON.parse()` and viceversa with `JSON.stringify()`. Modify the object and then transform it to string/JSON again — angrykoala, Jan 12 '17 at 14:51
Possible duplicate of [Safely turning a JSON string into an object](http://stackoverflow.com/questions/45015/safely-turning-a-json-string-into-an-object) — Stu, Jan 12 '17 at 14:52
function addQteSomme(data) { for(var i = 0; i < data.length; i++) { var delivery = data[i]; delivery.qte = delivery.as + delivery.dd } return data; } — Amine Hatim, Jan 12 '17 at 14:52
*"need also check if key exist or not"* - if *what* key exists, and what do you want to do if it does/doesn't? — deceze, Jan 12 '17 at 15:32

tymeJV · Answer 1 · 2017-01-12T15:02:32.317

3

Seems like you just want the sum of the existing keys, should be pretty simple using a couple .map commands and a .reduce:

return json.cmd.map(function(salesList) {
    return salesList.sales.map(function(sale) {
        var keysToAdd = ["qte1", "qte2"];

        sale.somme = Object.keys(sale).reduce(function(total, key) {
            return total += keysToAdd.indexOf(key) > -1 ? +sale[key] : 0;
        }, 0);

        return sale;
    });
});

Demo: https://jsfiddle.net/x294yt1h/

edited Jan 12 '17 at 15:02

answered Jan 12 '17 at 14:51

tymeJV

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Thanks @tymeJV it works. I did it in for loop but it's not elegant like yours – Amine Hatim Jan 12 '17 at 14:56
but in the object it will be have another keys that it will be not be added in total – Amine Hatim Jan 12 '17 at 14:59
@AmineHatim - Then this approach wont work - based on your example I assumed all keys would need to be added. – tymeJV Jan 12 '17 at 15:01
@AmineHatim - I've added a condition to check for specific keys and only add those. – tymeJV Jan 12 '17 at 15:02
I think my question wasn't clear I alter the JSON – Amine Hatim Jan 12 '17 at 15:33

score 1 · Answer 2 · answered Jan 12 '17 at 15:01

const data = 
{
    "cmd": [
        {
            "sales": [
                {
                    "qte1": "2",
                    "qte2": "3"
                },
                {
                    "qte1": "66"
                },
                {
                    "qte2": "77"
                }
            ]
        }
    ]
};

function sum(dataObj) {
    const hasCmd = dataObj && dataObj.cmd && dataObj.cmd.length > 0;
    const hasSales = hasCmd && dataObj.cmd[0].sales && dataObj.cmd[0].sales.length > 0;
    if (hasCmd && hasSales) {
        const clonedArray = dataObj.cmd[0].sales.slice();
        const summedArray = clonedArray.map(function(group) {
            const groupKeys = Object.keys(group);
            const sum = groupKeys.reduce(function (total, key) {
                return total + parseInt(group[key], 10 /* Decimal Radix */);
            }, 0);
            return Object.assign({}, group, { 'somme': sum.toString() });
        });
        // build a new object to return to include new summed array
        return { "cmd": [{ "sales": summedArray }] };
    }
    return dataObj;
}

console.log('data', JSON.stringify(data));
const newData = sum(data);
console.log('newData', JSON.stringify(newData));

Thanks @Rob Brander I think my question was not very clear I alter the JSON — Amine Hatim, Jan 12 '17 at 15:32

Mech45 · Answer 3 · 2017-01-12T15:22:32.427

Maybe you can first and formost refector your tree.

Like that :

{
  command: [
    {
      sales: [
        {
          quantity: [1, 2, 4],
          sum: 7
        }
      ]
    }
  ]
}

I don't know if your structure is open to any refectoring, but you must do something about it !

However, try to use the correct type of value in your row, and try to keep in mind to never mutate and object, use functor like map and reduce :

const cmd = [
    {
    sales: [
        {
          quantity: [1, 2, 3],
          sum: 0
        },
        {
          quantity: [67, 2, 3],
          sum: 0
        }
    ]
  }
];

const newObjectWithSum = cmd.map(sales => {
    return sales.sales.map((sale) => {
    sale.sum = sale.quantity.reduce((valueIn, next) => { 
        return valueIn + next;
    },0);
    return sale;
    });
})

Thanks @Steven leclerc I think my question wasn't clear I alter the JSON — Amine Hatim, Jan 12 '17 at 15:32

Addition keys in JSON

3 Answers3