Converting an object with key-value pairs into a regular array in Javascript

Question

Converting an object with key-value pairs into a regular array in Javascript

Is there a better method to convert an associative array to a standard array with 0 based indexes other than manually iterating and rewriting each item?

I have an array that was generated by tallying the occurrences of certain properties and it needs to remain in that format. The current array structure is as follows:

let ASSARR = { 
    "abc": { "c": 5, "p": 3 },
    "def": { "c": 1, "p": 10 },
    "ghi": { "c": 15, "p": 7 }
};

...and so on. After filtering and sorting the array, I need to transform it into a standard array format like this:

let STARR = [
    { "i": "abc", "c": 5, "p": 3 },
    { "i": "def", "c": 1, "p": 10 },
    { "i": "ghi", "c": 15, "p": 7 }
];

Is there a more efficient way to accomplish this task without using a traditional loop such as for?

javascript arrays

Answer 1

Answer №1

Is there a different method other than iteration and rewriting each item?

No, you will need to use a loop (either in your code, or in code in the standard library that you call such as looping through the result of Object.entries).

Since it involves a loop either way, I would recommend just writing the loop (especially because by doing so, you can loop just once instead of multiple times). Assuming you want to create new objects rather than simply adding an i property to the existing objects:

const result = [];
for (const i in ASSARR) {
    result.push({
        i,
        ...ASSARR[i],
    });
}

let ASSARR = { 
    "abc": { "c": 5, "p": 3 },
    "def": { "c": 1, "p": 10 },
    "ghi": { "c": 15, "p": 7 }
};
const result = [];
for (const i in ASSARR) {
    result.push({
        i,
        ...ASSARR[i],
    });
}
console.log(result);

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

If you wish to modify the existing objects instead:

const result = [];
for (const i in ASSARR) {
    const object = ASSARR[i];
    object.i = i;
    result.push(object);
}

let ASSARR = { 
    "abc": { "c": 5, "p": 3 },
    "def": { "c": 1, "p": 10 },
    "ghi": { "c": 15, "p": 7 }
};
const result = [];
for (const i in ASSARR) {
    const object = ASSARR[i];
    object.i = i;
    result.push(object);
}
console.log(result);

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

Note: The instructions assume that there are no inherited but enumerable properties that you want to exclude. If there are any, enclose the push calls in if (Object.hasOwn(object, i)) to skip inherited properties.

Answer 2

Is there a different method other than iteration and rewriting each item?

No, you will need to use a loop (either in your code, or in code in the standard library that you call such as looping through the result of Object.entries).

Since it involves a loop either way, I would recommend just writing the loop (especially because by doing so, you can loop just once instead of multiple times). Assuming you want to create new objects rather than simply adding an i property to the existing objects:

const result = [];
for (const i in ASSARR) {
    result.push({
        i,
        ...ASSARR[i],
    });
}

let ASSARR = { 
    "abc": { "c": 5, "p": 3 },
    "def": { "c": 1, "p": 10 },
    "ghi": { "c": 15, "p": 7 }
};
const result = [];
for (const i in ASSARR) {
    result.push({
        i,
        ...ASSARR[i],
    });
}
console.log(result);

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

If you wish to modify the existing objects instead:

const result = [];
for (const i in ASSARR) {
    const object = ASSARR[i];
    object.i = i;
    result.push(object);
}

let ASSARR = { 
    "abc": { "c": 5, "p": 3 },
    "def": { "c": 1, "p": 10 },
    "ghi": { "c": 15, "p": 7 }
};
const result = [];
for (const i in ASSARR) {
    const object = ASSARR[i];
    object.i = i;
    result.push(object);
}
console.log(result);

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

Note: The instructions assume that there are no inherited but enumerable properties that you want to exclude. If there are any, enclose the push calls in if (Object.hasOwn(object, i)) to skip inherited properties.

Answer 3

Answer №2

One way to retrieve the data is by extracting the entries and associating them with specific keys.

const
    object = { abc: { c: 5, p: 3 }, def: { c: 1, p: 10 }, ghi: { c: 15, p: 7 } },
    array = Object
        .entries(object)
        .map(([i, o]) => ({ i, ...o }));

console.log(array);

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

Answer 4

One way to retrieve the data is by extracting the entries and associating them with specific keys.

const
    object = { abc: { c: 5, p: 3 }, def: { c: 1, p: 10 }, ghi: { c: 15, p: 7 } },
    array = Object
        .entries(object)
        .map(([i, o]) => ({ i, ...o }));

console.log(array);

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

Answer 5

Answer №3

To achieve this, simply utilize Object.entries along with Array.map...

For example...

let data = { 
    "apple": { "price": 2, "quantity": 10 },
    "banana": { "price": 1, "quantity": 20 },
    "orange": { "price": 3, "quantity": 5 }
};

let modifiedData = Object.entries(data).map(([key,value]) => {
  return {item: key, ...value};
});

console.log(modifiedData);

Answer 6

To achieve this, simply utilize Object.entries along with Array.map...

For example...

let data = { 
    "apple": { "price": 2, "quantity": 10 },
    "banana": { "price": 1, "quantity": 20 },
    "orange": { "price": 3, "quantity": 5 }
};

let modifiedData = Object.entries(data).map(([key,value]) => {
  return {item: key, ...value};
});

console.log(modifiedData);

Converting an object with key-value pairs into a regular array in Javascript

Answer №1

Answer №2

Answer №3

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