Create duplicate array of object

Question

Say I have an array of object::

const banana = [{"a":"ann","b":"bann","det":[{"c":"cat","d":"dog"},{"c":"conn","d":"donn"}]}, {"a":"auu","b":"buu","det":[{"c":"camel","d":"damel"},{"c":"coww","d":"doww"}]}]

I want to transform this array of object in this form::

const banana =  [{"a":"ann","b":"bann","c":"cat","d":"dog"}, {"a":"ann","b":"bann","c":"conn","d":"donn"}, {"a":"auu","b":"buu","c":"camel","d":"damel"}, {"a":"auu","b":"buu","c":"coww","d":"doww"}]

As you can see array of object inside array of object have merged and duplicated.

I tried as:

const apple = []

for(let i = 0; i<banana.length;i++){
    for(let j = 0;j<banana[i].det.length;j++{
    apple.push(banana[i].det[j])
    }
}
console.log(apple)

**OUTPUT: [{c: "cat", d: "dog"},{c: "conn", d: "donn"},{c: "camel", d: "damel"},{c: "coww", d: "doww"}]**

But I'm looking for the O/P as:

[{"a":"ann","b":"bann","c":"cat","d":"dog"}, {"a":"ann","b":"bann","c":"conn","d":"donn"}, 
{"a":"auu","b":"buu","c":"camel","d":"damel"}, {"a":"auu","b":"buu","c":"coww","d":"doww"}]

But I'm unable to form logic. I'm still trying but if i could get some guidance that would be really helpful.

**EDIT:**So I've come up with an idea using spread operator:

let enamel = {}

for(let i = 0; i<banana.length;i++){
    for(let j = 0;j<banana[i].det.length;j++){
     employee = {
        ...banana[j],
        ...banana[i].det[j]
    };
    }
}

It gives the output as:

console.log(enamel) 
{a: "auu", b: "buu", det: Array(2), c: "coww", d: "doww"}

But I want to have all the objects in an array as previously stated.

General Grievance · Accepted Answer · 2022-10-24 16:58:46Z

1

You can use this logic, which copies over initial object, adds extra properties, drops the det array, and flatten the result

function extras(obj) {
  // create a copy of the current context (initial obj)
  // and add all properties from the extra object
  obj = Object.assign({}, this, obj);
  // but delete the `det` from the copy
  delete obj.det;
  // and return the object
  return obj;
}

// per each array object ...
banana
  .map(
    // and per each det ...
    obj => obj.det.map(extras, obj)
  )
  // flatten the final array of objects
  .flat();

edited Oct 24, 2022 at 16:58

General Grievance

5,12039 gold badges39 silver badges60 bronze badges

answered Jan 19, 2021 at 8:19

Andrea Giammarchi

3,2081 gold badge18 silver badges25 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Hassan Imam · Accepted Answer · 2021-01-19 09:17:28Z

0

You just have to extract a and b from object in banana. I have used destructuring to extract it.

const banana = [{ "a": "ann", "b": "bann", "det": [{ "c": "cat", "d": "dog" }, { "c": "conn", "d": "donn" }] }, { "a": "auu", "b": "buu", "det": [{ "c": "camel", "d": "damel" }, { "c": "coww", "d": "doww" }] }]
const apple = []

for (let i = 0; i < banana.length; i++) {
  for (let j = 0; j < banana[i].det.length; j++) {
      const {a,b} = banana[i];
      const {c,d} = banana[i].det[j];
      apple.push({a,b,c,d});
    }
}
console.log(apple)

edited Jan 19, 2021 at 9:17

answered Jan 19, 2021 at 8:19

Hassan Imam

22.6k6 gold badges45 silver badges53 bronze badges

7 Comments

Sushant Rad Over a year ago

Thank you this is exactly what I wanted. But could you help me understand line 6 i.e.: const {a,b} = banana[i]; What exactly it does?

Hassan Imam Over a year ago

developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/… You can read about this on the link. It is like accessing variable a and b.

Sushant Rad Over a year ago

I cannot use this solution as spread operator give some random value in node js. Can you suggest some other way?

Sushant Rad Over a year ago

Does it take browser property as well...because in response it gives me:: "__parentArray" and other random keys along with the value

Hassan Imam Over a year ago

No, it shouldn't unless your object is different. You can use extract both c and d. You can check now if the current solution works for you.

|

JeannotMn · Accepted Answer · 2021-01-19 08:19:00Z

0

You can do this:

const banana = [
        { 
            "a": "ann", 
            "b": "bann",
            "det": [{ "c": "cat", "d": "dog" }, { "c": "conn", "d": "donn" }]
        }, 

        { 
            "a": "auu", 
            "b": "buu", 
            "det": [
                { "c": "camel", "d": "damel" },
                { "c": "coww", "d": "doww" }
            ] 
        }
    ]

    const result = [];
    banana.forEach( b =>{
        b.det.forEach(d =>{
            result.push({
                a: b.a,
                b: b.b,
                c: d.c,
                d: d.d
            });
        });
    });

    console.log(result);

answered Jan 19, 2021 at 8:19

JeannotMn

2352 silver badges10 bronze badges

Comments

Naren · Accepted Answer · 2021-01-19 08:22:59Z

0

Try this

const banana = [{"a":"ann","b":"bann","det":[{"c":"cat","d":"dog"},{"c":"conn","d":"donn"}]}, {"a":"auu","b":"buu","det":[{"c":"camel","d":"damel"},{"c":"coww","d":"doww"}]}]

const output = []

for (const { a, b, det } of banana) {
  for (const animal of det) {
    output.push({a, b, ...animal })
  }
}

console.log(output)

answered Jan 19, 2021 at 8:22

Naren

4,5293 gold badges20 silver badges32 bronze badges

Comments

mss · Accepted Answer · 2021-01-19 08:46:54Z

0

I think you want to do it like this in case you want to avoid manually take a and b and other property except 'det' properties

function getResult(banana) {

    const answer = [];

    banana.forEach(element => {
        const arrayData = element['det'];
        delete element['det'];
        // remove the 'del' property temporarily

        arrayData.forEach(subElement  => {
            answer.push({
                ...element, // basically spread operator to make copy of all properties each time
                ...subElement
            });
        });

        // restore the 'del' proprty
        element['det'] = arrayData;
    });

    console.log("the result is : ", answer);
    return answer;
}

edited Jan 19, 2021 at 8:46

answered Jan 19, 2021 at 8:33

mss

1,5032 gold badges10 silver badges19 bronze badges

Collectives™ on Stack Overflow

Create duplicate array of object

5 Answers 5

Comments

7 Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

Comments

7 Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related