Why am I receiving varied results when trying to filter for distinct date values?

Question

Why am I receiving varied results when trying to filter for distinct date values?

While attempting to filter unique dates, I've noticed that the output varies. In some cases, it works correctly, while in others, it does not. I'm having trouble figuring out what's causing this inconsistency. The filtering method below generally works well, but occasionally fails.

The goal is to extract all unique dates from both the RatingsDaily["2"] and RatingsDaily["4"] arrays.

// Data example:
const RatingsDaily = {
    "2": [
        {"2021-12-24": 3.21}, 
        {"2021-12-25": 3.19}, 
        {"2021-12-28": 3.29}, 
        {"2021-12-29": 3.24}, 
        {"2021-12-30": 3.38},
    ], 
    "4": [
        {"2021-12-24": 1.0}, 
        {"2021-12-25": 1.0}, 
        {"2021-12-26": 1.0}, 
        {"2022-01-27": 2.0}, 
        {"2022-01-03": 5.0}, 
        {"2022-01-05": 1.0},
    ]
}

// Current implementation:
let labels = []
let uniquelabel = []

for (let i = 0; i < RatingsDaily["2"].length; i++) {
    uniquelabel.push(Object.keys(RatingsDaily["2"][i]));
}

for (let i = 0; i < RatingsDaily["4"].length; i++) {
    uniquelabel.push(Object.keys(RatingsDaily["4"][i]));
}

const useFilter = arr => {
    return arr.filter((value, index, self) => {
        return self.indexOf(value) === index;
    });
};

const result = useFilter(uniquelabel);

console.log(result)

I would greatly appreciate any guidance on how to resolve this issue. Thank you for your assistance.

javascript arrays json

Answer 1

Answer №1

Consider utilizing a Set instead as it is specifically designed to store unique values. Additionally, it may be beneficial to dynamically handle the different types of ratings present, rather than hard-coding values like 2 and 4. You can achieve this by iterating over the keys in the RatingsDaily object. See an example implementation below:

const RatingsDaily = {"2": [{"2021-12-24": 3.21},{"2021-12-25": 3.19},{"2021-12-28": 3.29},{"2021-12-29": 3.24},{"2021-12-30": 3.38},], "4": [{"2021-12-24": 1.0},{"2021-12-25": 1.0},{"2021-12-26": 1.0},{"2022-01-27": 2.0},{"2022-01-03": 5.0},{"2022-01-05": 1.0}]}

const datesSet = new Set();
for (const rating of Object.keys(RatingsDaily)) {
    for (const dateObj of RatingsDaily[rating]) {
        datesSet.add(Object.keys(dateObj)[0]);
    }
}
const datesArr = Array.from(datesSet);
console.log(datesArr);

Answer 2

Consider utilizing a Set instead as it is specifically designed to store unique values. Additionally, it may be beneficial to dynamically handle the different types of ratings present, rather than hard-coding values like 2 and 4. You can achieve this by iterating over the keys in the RatingsDaily object. See an example implementation below:

const RatingsDaily = {"2": [{"2021-12-24": 3.21},{"2021-12-25": 3.19},{"2021-12-28": 3.29},{"2021-12-29": 3.24},{"2021-12-30": 3.38},], "4": [{"2021-12-24": 1.0},{"2021-12-25": 1.0},{"2021-12-26": 1.0},{"2022-01-27": 2.0},{"2022-01-03": 5.0},{"2022-01-05": 1.0}]}

const datesSet = new Set();
for (const rating of Object.keys(RatingsDaily)) {
    for (const dateObj of RatingsDaily[rating]) {
        datesSet.add(Object.keys(dateObj)[0]);
    }
}
const datesArr = Array.from(datesSet);
console.log(datesArr);

Answer 3

Answer №2

Here is a concise version:

const RatingsDaily = {"2": [{"2021-12-24": 3.21},{"2021-12-25": 3.19},{"2021-12-28": 3.29},{"2021-12-29": 3.24},{"2021-12-30": 3.38},], "4": [{"2021-12-24": 1.0},{"2021-12-25": 1.0},{"2021-12-26": 1.0},{"2022-01-27": 2.0},{"2022-01-03": 5.0},{"2022-01-05": 1.0}]}

const result = [...new Set( // ensures uniqueness
    Object.values(RatingsDaily).flat() // fetches all entries
    .map(Object.keys).flat() // retains only string dates
  )]

console.log(result);

Answer 4

Here is a concise version:

const RatingsDaily = {"2": [{"2021-12-24": 3.21},{"2021-12-25": 3.19},{"2021-12-28": 3.29},{"2021-12-29": 3.24},{"2021-12-30": 3.38},], "4": [{"2021-12-24": 1.0},{"2021-12-25": 1.0},{"2021-12-26": 1.0},{"2022-01-27": 2.0},{"2022-01-03": 5.0},{"2022-01-05": 1.0}]}

const result = [...new Set( // ensures uniqueness
    Object.values(RatingsDaily).flat() // fetches all entries
    .map(Object.keys).flat() // retains only string dates
  )]

console.log(result);

Answer 5

Answer №3

The array uniquelabel consists of one-element sub-arrays. It seems like this may not be your intended structure; perhaps you were aiming for an array of strings (dates) instead of arrays. To rectify this, simply make two adjustments as suggested below.

Replace:

uniquelabel.push(Object.keys(RatingsDaily[n][i]));

With:

uniquelabel.push(...Object.keys(RatingsDaily[n][i]));

In essence, utilize the spread operator to insert a string into uniquelabel rather than an array.

DEMO

// Given data
const RatingsDaily = { "2": [ {"2021-12-24": 3.21}, {"2021-12-25": 3.19}, {"2021-12-28": 3.29}, {"2021-12-29": 3.24}, {"2021-12-30": 3.38}, ], "4": [ {"2021-12-24": 1.0}, {"2021-12-25": 1.0}, {"2021-12-26": 1.0}, {"2022-01-27": 2.0}, {"2022-01-03": 5.0}, {"2022-01-05": 1.0}, ] };

// Approach taken
let labels = []
let uniquelabel = []

for (let i = 0; i < RatingsDaily["2"].length; i++) {
    uniquelabel.push(...Object.keys(RatingsDaily["2"][i]));
}

for (let i = 0; i < RatingsDaily["4"].length; i++) {
    uniquelabel.push(...Object.keys(RatingsDaily["4"][i]));
}

const useFilter = arr => {
    return arr.filter((value, index, self) => {
        return self.indexOf(value) === index;
    });
};

const result = useFilter(uniquelabel);

console.log(result)

Answer 6

The array uniquelabel consists of one-element sub-arrays. It seems like this may not be your intended structure; perhaps you were aiming for an array of strings (dates) instead of arrays. To rectify this, simply make two adjustments as suggested below.

Replace:

uniquelabel.push(Object.keys(RatingsDaily[n][i]));

With:

uniquelabel.push(...Object.keys(RatingsDaily[n][i]));

In essence, utilize the spread operator to insert a string into uniquelabel rather than an array.

DEMO

// Given data
const RatingsDaily = { "2": [ {"2021-12-24": 3.21}, {"2021-12-25": 3.19}, {"2021-12-28": 3.29}, {"2021-12-29": 3.24}, {"2021-12-30": 3.38}, ], "4": [ {"2021-12-24": 1.0}, {"2021-12-25": 1.0}, {"2021-12-26": 1.0}, {"2022-01-27": 2.0}, {"2022-01-03": 5.0}, {"2022-01-05": 1.0}, ] };

// Approach taken
let labels = []
let uniquelabel = []

for (let i = 0; i < RatingsDaily["2"].length; i++) {
    uniquelabel.push(...Object.keys(RatingsDaily["2"][i]));
}

for (let i = 0; i < RatingsDaily["4"].length; i++) {
    uniquelabel.push(...Object.keys(RatingsDaily["4"][i]));
}

const useFilter = arr => {
    return arr.filter((value, index, self) => {
        return self.indexOf(value) === index;
    });
};

const result = useFilter(uniquelabel);

console.log(result)

Answer 7

Answer №4

If you're looking for a solution, this snippet of code could be exactly what you need:

let uniqueLabels = [];

for(let i = 0; i < RatingsDaily[2].length; i++) {
    uniqueLabels.push(Object.keys(RatingsDaily[2][i])[0]);
}

for(let i = 0; i < RatingsDaily[4].length; i++) {
    uniqueLabels.push(Object.keys(RatingsDaily[4][i])[0]);
}

const filterDuplicates = (arr) => {
    return arr.sort().filter((value, index, self) => {
        return !index || value != self[index - 1];
    });
};

const finalResult = filterDuplicates(uniqueLabels);

console.log(finalResult);

Answer 8

If you're looking for a solution, this snippet of code could be exactly what you need:

let uniqueLabels = [];

for(let i = 0; i < RatingsDaily[2].length; i++) {
    uniqueLabels.push(Object.keys(RatingsDaily[2][i])[0]);
}

for(let i = 0; i < RatingsDaily[4].length; i++) {
    uniqueLabels.push(Object.keys(RatingsDaily[4][i])[0]);
}

const filterDuplicates = (arr) => {
    return arr.sort().filter((value, index, self) => {
        return !index || value != self[index - 1];
    });
};

const finalResult = filterDuplicates(uniqueLabels);

console.log(finalResult);

Why am I receiving varied results when trying to filter for distinct date values?

Answer №1

Answer №2

Answer №3

Answer №4

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