Guide on generating an array of objects using values nested within a parent object

Question

Guide on generating an array of objects using values nested within a parent object

I have multiple layers of objects nested within a main object like this:

var initialObj = { 
   firstKey: {
     x: true,
     y: 5
   },
   secondKey: {
     x: false,
     y: 10
   },
   thirdKey: {
     x: true,
     y: 15
   }
}

My goal is to extract an array of objects based on certain conditions within the nested objects. This array will also include the corresponding keys in a [key,value] format, similar to this:

resultingArray = [
  {
    x: true,
    y: 5,
    z: "firstKey" 
  },
  {
    x: true,
    y: 15,
    z: "thirdKey"
  }
]

javascript arrays object

Answer 1

Answer №1

To easily loop through the parentObj and extract specific data, you can utilize a for...in loop as demonstrated below:

var extractedData = [];
for(var property in parentObj){
   var obj = parentObj[property];
   if(obj.a) {
      extractedData.push({a: obj.a, b: obj.b, c: property });
   }
}

Answer 2

To easily loop through the parentObj and extract specific data, you can utilize a for...in loop as demonstrated below:

var extractedData = [];
for(var property in parentObj){
   var obj = parentObj[property];
   if(obj.a) {
      extractedData.push({a: obj.a, b: obj.b, c: property });
   }
}

Answer 3

Answer №2

Firstly, it's important to note that

In JavaScript, associative arrays are not a native concept.

You can check out more information here.

In the provided example, "key1" is duplicated. If you wish to store data like this, then you need to use an Array, especially if one of the values in the nested objects holds the value true.

var parentObj = {
   key1: [
       {
         a: true,
         b: 2
       },
       {
         a: false,
         b: 2
       }
   ],
   key3: [
       {
         a: true,
         b: 2
       }
   ]
};

To achieve what you want, make use of the following approach:

var parentObj = {
   key1: [
       {
         a: true,
         b: 2
       },
       {
         a: false,
         b: 2
       }
   ],
   key3: [
       {
         a: true,
         b: 2
       }
   ]
};
var myArray = [];
for(var key in parentObj){
   var childObj = parentObj[key];
   var res = childObj.filter(function(element){
       return  element.a == true;
   });
   for(ele in res){
       res[ele].c = key;
   }
   if(res.length > 0){
       // if you want any of element having true property
       myArray.push(res[0]);
   }
}
console.log(myArray);

Answer 4

Firstly, it's important to note that

In JavaScript, associative arrays are not a native concept.

You can check out more information here.

In the provided example, "key1" is duplicated. If you wish to store data like this, then you need to use an Array, especially if one of the values in the nested objects holds the value true.

var parentObj = {
   key1: [
       {
         a: true,
         b: 2
       },
       {
         a: false,
         b: 2
       }
   ],
   key3: [
       {
         a: true,
         b: 2
       }
   ]
};

To achieve what you want, make use of the following approach:

var parentObj = {
   key1: [
       {
         a: true,
         b: 2
       },
       {
         a: false,
         b: 2
       }
   ],
   key3: [
       {
         a: true,
         b: 2
       }
   ]
};
var myArray = [];
for(var key in parentObj){
   var childObj = parentObj[key];
   var res = childObj.filter(function(element){
       return  element.a == true;
   });
   for(ele in res){
       res[ele].c = key;
   }
   if(res.length > 0){
       // if you want any of element having true property
       myArray.push(res[0]);
   }
}
console.log(myArray);

Answer 5

Answer №3

Here is a concise solution: by extracting keys from the main object, we can iterate over them to create new objects and then filter out any falsy values:

const mainObject = { 
   key1: {
     a: true,
     b: 2
   },
   key2: {
     a: false,
     b: 2
   },
   key3: {
     a: true,
     b: 2
   }
};

const finalResult = Object.keys(mainObject)
    .map(key => (Object.assign({}, mainObject[key], {c: key})))
    .filter(({a}) => a);

console.log(finalResult);

Answer 6

Here is a concise solution: by extracting keys from the main object, we can iterate over them to create new objects and then filter out any falsy values:

const mainObject = { 
   key1: {
     a: true,
     b: 2
   },
   key2: {
     a: false,
     b: 2
   },
   key3: {
     a: true,
     b: 2
   }
};

const finalResult = Object.keys(mainObject)
    .map(key => (Object.assign({}, mainObject[key], {c: key})))
    .filter(({a}) => a);

console.log(finalResult);

Guide on generating an array of objects using values nested within a parent object

Answer №1

Answer №2

Answer №3

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