How can I sort a complex JSON object efficiently?

Question

My JSON object consists of several nestings:

{
"myJson": {
  "firstGroup": {
"0": [
                {
                    "month": 1.0,
                    "amount": 1.7791170955479318,
                    "name": "dummy1",
                    "nr": 3
                },
                {
                    "month": 2.0,
                    "amount": 324.0,
                    "name": "dummy2",
                    "nr": 1
                },
                {
                    "month": 3.0,
                    "amount": 32323.0,
                    "name": "dummy3",
                    "nr": 2
                }
],
"yearlyResults": {
"0": [
{
                    "month": 1.0,
                    "amount": 100000,
                    "name": "dummy1",
                    "nr": 3
                },
                {
                    "month": 2.0,
                    "amount": 3000000,
                    "name": "dummy2",
                    "nr": 1
                },
                {
                    "month": 3.0,
                    "amount": 60000,
                    "name": "dummy3",
                    "nr": 2
                }
]
}           
 },
 "secondGroup": {
// Built the same way as firstGroup 
 }
},
"success": true
}

In this JSON I want to sort the data in the seperate groups in "0" and "yearlyResults" in ascending order....

My Code:

/**
   * Function to sort data ascending
   * @param property any
   */
  sortByProperty(property) {
    return (a, b) => {
      if (a[property] > b[property]) {
        return 1;
      }
      else if (a[property] < b[property]) {
        return -1;
      }
      return 0;
    };
  }

 /**
   * Show sorted data in this function
   */
private getSortedData() {
this.myService.getData().subscribe();
(resp: any) => {
const data = resp.success ? resp.myJson : null;
        // firstGroup for sort
        const firstData = data['firstGroup'];
        const currentFirstData = firstData['0'];
        const currentFirstYearly = firstData.yearlyResults['0'];

         // secondGroup for sort
        const secondData = data['secondGroup'];
        const currentSecondData = secondData['0'];
        const currentSecondYearly = secondData.yearlyResults['0'];

  if (null !== data && data) {
 currentFirstData.sort(this.sortByProperty('nr'));
 currentFirstYearly.sort(this.sortByProperty('nr'));
 currentcurrentSecondData.sort(this.sortByProperty('nr'));
 currentSecondYearly.sort(this.sortByProperty('nr'));
...
}
}
}

My solution approach works, however I don't find it efficient enough! With two groups it is still ok to sort so, but if I have 20 or 30 I can no longer perform so. Can I sort the JSON groups by iterating somehow? Can you help me please?

The groups are all structured in the same way. There are "0" and "yearlyResults". These are to be sorted in ascending order. Do you know how to do this? — , Jun 29 '21 at 08:32
Are the properties of your object added later or does object have all properties at the time of creation? Because adding them later will significantly slow down property access speeds — Bertramp, Jun 29 '21 at 08:41

Yuriy Yakym · Accepted Answer · 2021-06-29T08:53:52.907

You can you Object.entries in order to iterate thought all key-value pairs and then use Array.prototype.reduce for composing the new object. Like so:

const data = JSON.parse('{ "myJson": { "firstGroup": { "0": [ { "month": 1.0, "amount": 1.7791170955479318, "name": "dummy1", "nr": 3 }, { "month": 2.0, "amount": 324.0, "name": "dummy2", "nr": 1 }, { "month": 3.0, "amount": 32323.0, "name": "dummy3", "nr": 2 } ], "yearlyResults": { "0": [ { "month": 1.0, "amount": 100000, "name": "dummy1", "nr": 3 }, { "month": 2.0, "amount": 3000000, "name": "dummy2", "nr": 1 }, { "month": 3.0, "amount": 60000, "name": "dummy3", "nr": 2 } ] } } }, "success": true }');

const object = data.myJson;

const sortSubGroupByProperty = (subGroup, property) => {
  return subGroup.sort((a, b) => {
    if (a[property] > b[property]) {
      return 1;
    }
    else if (a[property] < b[property]) {
      return -1;
    }
    return 0;
  });
}

const result = Object.entries(object).reduce((result, entry) => {
  const [groupName, group] = entry;
  result[groupName] = {
    ...group,
    0: sortSubGroupByProperty(group[0], 'nr'),
    yearlyResults: {
        ...group.yearlyResults,
        0: sortSubGroupByProperty(group.yearlyResults[0], 'nr')
    }
  };
  return result;
}, {});

console.log(result);

By ...group i have Error TS2698: Spread types may only be created from object types. — , Jun 29 '21 at 09:00
This might help to fix the problem: https://stackoverflow.com/questions/51189388/typescript-spread-types-may-only-be-created-from-object-types — Yuriy Yakym, Jun 29 '21 at 09:03

score 0 · Answer 2 · answered Jun 29 '21 at 09:09

Here in the snippet everything runs without errors.I have the problem in the IDE. I have implemented the code like this:

this.kpisService.getAllKpisMonthData(yearString).subscribe(
  (resp: any) => {
    const data = resp.success ? resp.kpi : null;

    // console.table(data);

    if (null !== data && data) {
      const sortSubGroupByProperty = (subGroup, property) => {
        return subGroup.sort((a, b) => {
          if (a[property] > b[property]) {
            return 1;
          }
          else if (a[property] < b[property]) {
            return -1;
          }
          return 0;
        });
      };

      const result = Object.entries(data).reduce((result, entry) => {
        const [groupName, group] = entry;
        result[groupName] = {
          ...group, // Here is the problem
          0: sortSubGroupByProperty(group[0], 'nr'),
          yearlyResults: {
            ...group.yearlyResults,
            0: sortSubGroupByProperty(group.yearlyResults[0], 'nr')
          }
        };
        return result;
      }, {});

      console.log(result);

How can I sort a complex JSON object efficiently?

2 Answers2