Not able to convert the object of JSON to key/value pair in Angular 7

Question

I need to convert my JSON data from like this :

 cacheMapDataDto = [{
    "cacheName": "cache_nchl_individual_type",
    "count": 2,
    "mapObj": {
      "NCHL_BI_BATCH_VERIFICATION": false,
      "NCHL_STL_BATCH_VERIFICATION": false
    },
    "nameOfCache": "NCHL Verification Status"
 }]

To this:

{"cacheName":"cache_member_dto_type",
"count":1,
"mapOfDto":[{"id":merCode,"value":"1"},{"id":merName,"value":"DE"},{"id":merId,"value":"10"}]
"nameOfCache":"Member DTO"
};

So ,I tried to convert the mapOfDto to key/value pair using following approach:

formatData(cacheMapDataDto:any){

  console.log("abc");

   console.log(cacheMapDataDto);


  this.result = Object.keys(cacheMapDataDto.mapOfDto).map(function(key) {
    return this.result[key] =cacheMapDataDto.mapOfDto[key], this.result;
  });

  console.log(this.result);

  this.cacheNewData={
  "cacheName":cacheMapDataDto.cacheName,
  "count":cacheMapDataDto.count,
  "mapOfDto":this.result,
  "nameOfCache": cacheMapDataDto.nameOfCache

  };

  console.log(this.cacheNewData);


  }

But,I got the error as:

TypeError: Cannot convert undefined or null to object
    at Function.keys (<anonymous>)
    at CacheMetaDataComponent.formatData

I am getting error at this line of code when I see where is the error coming from ts file:

 this.result = Object.keys(cacheMapDataDto.mapOfDto).map(function(key) {
    return this.result[key] =cacheMapDataDto.mapOfDto[key], this.result;
  });

Is there any good approach?

Hi Ashwin, hope this help : your "Cannot convert undefined or null to object" error depends on how you're accessing your object. Regarding your conversion just need to change it a bit to : `this.result = Object.keys(cacheMapDataDto).map(function(key) { return { "id": key, "value": cacheMapDataDto[key]}; });` Hope this helps. — jérémy Darchy, Sep 25 '19 at 09:17

Adrita Sharma · Accepted Answer · 2019-09-25T10:40:41.390

1

Based on your modified question, try this:

this.cacheMapDataDto.forEach(cacheMapDataDto => {
      let result = Object.assign(cacheMapDataDto)
      result.mapObj = Object.keys(cacheMapDataDto.mapObj).map(key => ({ key, value: cacheMapDataDto.mapObj[key] }));
})

Working Stackbiltz

edited Sep 25 '19 at 10:40

answered Sep 25 '19 at 08:46

Adrita Sharma

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Not able to convert the object of JSON to key/value pair in Angular 7

1 Answers1