Why I am getting different output while filtering unique date values?-CodePudding

I am getting different output while filtering unique dates .. It is working correctly in some case and incorrect in some for example below..I am not able figure what is the problem..Below filtering method works good on most cases but fails in some..

I want to get all unique dates from RatingsDaily["2"] array and RatingsDaily["4"] array

// This is the 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},
    ]
}

// This is the way I am doing
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)

Any help would be appreciated..Thank you in advance

CodePudding user response：

It might be better to use a Set since it is designed to only keep unique values. Also, you may have more types of ratings, so it might be better to not hard-code 2 and 4 explicitly, but consider whatever keys are present in RatingsDaily object. One example way to do is 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);

CodePudding user response：

A short alternative:

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( // will make values unique
    Object.values(RatingsDaily).flat() // lists all entries
    .map(Object.keys).flat() // retains string dates only
  )]

console.log(result);

CodePudding user response：

The array uniquelabel is an array one-element sub-arrays. I don't think this is what you intended; you probably wanted an array of strings (dates), not an array of arrays. To fix that just change two lines and you'll be good.

Change:

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

To:

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

In other words use the spread operator to put as string and not an array into uniquelabel.

DEMO

// This is the 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}, ] };

// This is the way I am doing
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)

CodePudding user response：

This code should work for you:

let uniquelabel = [];

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

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

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

const result = useFilter(uniquelabel);

console.log(result);