This simple (as before, I thought) transformation of a JavaScript object defeats me. I would like to flatten this object in the following way.

This is what I have:

{
    "1": {
        "group": "Clothes",
        "brand": {
            "0": {
                "brand_id": "12",
                "brand_name": "Adidas"
            },
            "1": {
                "brand_id": "15",
                "brand_name": "Zara"
            }
        }
    },
    "2": {
        "group": "Cars",
        "brand": {
            "0": {
                "brand_id": "43",
                "brand_name": "Ferrari"
            },
            "1": {
                "brand_id": "51",
                "brand_name": "BMW"
            }
        }
    }
}

And this is it, what I want to get

{0: {
    brand_id: "12",
    brand_name: "Adidas",
    group: "Clothes",
}
1: {
    brand_id: "15",
    brand_name: "Zara",
    group: "Clothes",
},
2: {
    brand_id: "43",
    brand_name: "Ferrari",
    group: "Cars",
}
3: {
    brand_id: "51",
    brand_name: "BMW",
    group: "Cars",
}}

I tried using .reduce() or .map() but ineffectively.

This simple (as before, I thought) transformation of a JavaScript object defeats me. I would like to flatten this object in the following way.

This is what I have:

{
    "1": {
        "group": "Clothes",
        "brand": {
            "0": {
                "brand_id": "12",
                "brand_name": "Adidas"
            },
            "1": {
                "brand_id": "15",
                "brand_name": "Zara"
            }
        }
    },
    "2": {
        "group": "Cars",
        "brand": {
            "0": {
                "brand_id": "43",
                "brand_name": "Ferrari"
            },
            "1": {
                "brand_id": "51",
                "brand_name": "BMW"
            }
        }
    }
}

And this is it, what I want to get

{0: {
    brand_id: "12",
    brand_name: "Adidas",
    group: "Clothes",
}
1: {
    brand_id: "15",
    brand_name: "Zara",
    group: "Clothes",
},
2: {
    brand_id: "43",
    brand_name: "Ferrari",
    group: "Cars",
}
3: {
    brand_id: "51",
    brand_name: "BMW",
    group: "Cars",
}}

I tried using .reduce() or .map() but ineffectively.

• javascript
• arrays
• typescript
• for-loop
• filter

• 1 The posted question does not appear to include any attempt at all to solve the problem. StackOverflow expects you to try to solve your own problem first, as your attempts help us to better understand what you want. Please edit the question to show what you've tried, so as to illustrate a specific problem you're having in a minimal reproducible example. For more information, please see How to Ask and take the tour. – CertainPerformance Commented Nov 2, 2018 at 6:51
• It looks like you've copied the data from a debugger somewhere, you might want to clarify the object/array structure there. What you have in your first block isn't valid JSON (or hjavascript). – Evan Trimboli Commented Nov 2, 2018 at 6:53
• 2 The Object data is incorrect.. Correct please – Yosvel Quintero Commented Nov 2, 2018 at 6:53

3 Answers 3

You can do:

const data = {1: {group: 'Clothes',brand: [{0: {brand_id: '12',brand_name: 'Adidas'}},{1: {brand_id: '15',brand_name: 'Zara'}}]},2: {group: 'Cars',brand: [{0: {brand_id: '43',brand_name: 'Ferrari'}},{1: {brand_id: '51',brand_name: 'BMW'}}]}};
const result = {};

Object.keys(data).forEach(k => {
  data[k].brand.forEach((b, i) => {
    result[Object.keys(result).length] = {
      brand_id: b[i].brand_id,
      brand_name: b[i].brand_name,
      group: data[k].group
    };
  });
});

console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }

This Object is kind of weird like array-like objects, but index start from 1 not 0, and lack of length.

Fix some typo first, brand should be object not array.

var objectOri = {
    1: {
        group: 'Clothes',
        brand: {
            0: {
                brand_id: "12",
                brand_name: "Adidas"
            },
            1: {
                brand_id: "15",
                brand_name: "Zara"
            }
        }
    },
    2: {
        group: 'Cars',
        brand: {
            0: {
                brand_id: "43",
                brand_name: "Ferrari"
            },
            1: {
                brand_id: "51",
                brand_name: "BMW"
            }
        }
    }
};

let arr = [];
Object.keys(objectOri).forEach(index => {
    let brand = objectOri[index].brand;
    Object.keys(brand).forEach(brIndex => {
        arr.push({
            ...brand[brIndex],
            group: objectOri[index].group
        });
    });
});


console.log(Object.assign({}, arr))

 

Also, if this obejct is a array-like object, the key should start from 0 not 1, and length is also necessary, like below.

var objectOri = {
    0: {
        group: 'Clothes',
        brand: {
            0: {
                brand_id: "12",
                brand_name: "Adidas"
            },
            1: {
                brand_id: "15",
                brand_name: "Zara"
            },
            length: 2
        }
    },
    1: {
        group: 'Cars',
        brand: {
            0: {
                brand_id: "43",
                brand_name: "Ferrari"
            },
            1: {
                brand_id: "51",
                brand_name: "BMW"
            },
            length: 2
        }
    },
    length: 2
};

let arr = [];
Array.from(objectOri).forEach(item => {
    Array.from(item.brand).forEach(brand => {
        arr.push({
            ...brand,
            group: item.group
        });
    });
});


console.log(Object.assign({}, arr))

 

let input = { "1": { "group": "Clothes", "brand": { "0": { "brand_id": "12", "brand_name": "Adidas"}, "1": { "brand_id": "15",                    "brand_name": "Zara"}} },
              "2": { "group": "Cars", "brand": { "0": { "brand_id": "43","brand_name": "Ferrari"},                "1": { "brand_id": "51", "brand_name": "BMW"}}}}

output = {}
Object.values(input).forEach(({ group, brand })=> {
  Object.values(brand).forEach(({ brand_id, brand_name })=>{      
    output[Object.keys(output).length]= {
      brand_id,
      brand_name,
      group,
    }
  })
})

console.log(output)