Ways to determine the occurrence rate of a specific value within a collection of dictionaries?

Question

Ways to determine the occurrence rate of a specific value within a collection of dictionaries?

Consider the array of dictionaries below:

var dictionary_demo = [
                         [
                            {country: "georgia", value: sunny},
                            {country: "france", value: rainy}
                         ],
                         [
                            {country: "georgia", value: sunny},
                            {country: "france", value: gloomy}
                         ],
                         [
                            {country: "georgia", value: rainy},
                            {country: "france", value: dry}
                         ]
                      ]

I'm trying to find out how many times each weather condition occurs in each country. Here's the desired output:

In Georgia: Sunny occurs twice and Rainy occurs once.

In France: Rainy occurs once, Gloomy occurs once, and Dry occurs once.

javascript arrays sorting dictionary frequency

Answer 1

Answer №1

Utilizing an array of arrays (JS term for a dictionary in JS is actually an array), you can efficiently employ the flatMap function to extract all values from the inner arrays and merge them into the main array. Subsequently, you have the ability to loop through the flattened array and gather the desired values.

In this particular scenario, I would opt for utilizing the array.reduce method to convert the resultant flattened array into an object where each country has a specific key associated with it. This key corresponds to another object containing keys representing different weather types and their respective frequency of occurrence.

var dictionary_demo = [
                         [
                            {country: "georgia", value: "sunny"},
                            {country: "france", value: "rainy"}
                         ],
                         [
                            {country: "georgia", value: "sunny"},
                            {country: "france", value: "gloomy"}
                         ],
                         [
                            {country: "georgia", value: "rainy"},
                            {country: "france", value: "dry"}
                         ]
                      ]

function weatherFrequency(arr) {
  // Flatten the given array
  const flatArr = arr.flatMap(a => a)

  // Use the flattened array to generate frequencies for each value
  const sortedArr = flatArr.reduce((accum, { country, value }) => {

    // Check for the existence of the key, add if absent
    if (!accum[country]) accum[country] = {}

    // Determine frequency of weather type occurrence within a country
    accum[country][value] ? accum[country][value] += 1 : accum[country][value] = 1

    // Return accumulator for next iteration of `reduce`
    return accum
  }, {})
  return sortedArr
}

// Verify the resulting object obtained from the `reduce` operation
console.log(weatherFrequency(dictionary_demo))

// Construct a string containing the desired values
const countryWeather = weatherFrequency(dictionary_demo)

// Implement string interpolation to access required information
console.log(`In Georgia: sunny occurs ${countryWeather.georgia.sunny} times, while rainy occurs ${countryWeather.georgia.rainy} time`)

``

Answer 2

Utilizing an array of arrays (JS term for a dictionary in JS is actually an array), you can efficiently employ the flatMap function to extract all values from the inner arrays and merge them into the main array. Subsequently, you have the ability to loop through the flattened array and gather the desired values.

In this particular scenario, I would opt for utilizing the array.reduce method to convert the resultant flattened array into an object where each country has a specific key associated with it. This key corresponds to another object containing keys representing different weather types and their respective frequency of occurrence.

var dictionary_demo = [
                         [
                            {country: "georgia", value: "sunny"},
                            {country: "france", value: "rainy"}
                         ],
                         [
                            {country: "georgia", value: "sunny"},
                            {country: "france", value: "gloomy"}
                         ],
                         [
                            {country: "georgia", value: "rainy"},
                            {country: "france", value: "dry"}
                         ]
                      ]

function weatherFrequency(arr) {
  // Flatten the given array
  const flatArr = arr.flatMap(a => a)

  // Use the flattened array to generate frequencies for each value
  const sortedArr = flatArr.reduce((accum, { country, value }) => {

    // Check for the existence of the key, add if absent
    if (!accum[country]) accum[country] = {}

    // Determine frequency of weather type occurrence within a country
    accum[country][value] ? accum[country][value] += 1 : accum[country][value] = 1

    // Return accumulator for next iteration of `reduce`
    return accum
  }, {})
  return sortedArr
}

// Verify the resulting object obtained from the `reduce` operation
console.log(weatherFrequency(dictionary_demo))

// Construct a string containing the desired values
const countryWeather = weatherFrequency(dictionary_demo)

// Implement string interpolation to access required information
console.log(`In Georgia: sunny occurs ${countryWeather.georgia.sunny} times, while rainy occurs ${countryWeather.georgia.rainy} time`)

``

Answer 3

Answer №2

var dictionary_example = [
   [
      {country: "germany", condition: "cloudy"},
      {country: "italy", condition: "sunny"}
   ],
   [
      {country: "germany", condition: "windy"},
      {country: "italy", condition: "rainy"}
   ],
   [
      {country: "germany", condition: "snowy"},
      {country: "italy", condition: "foggy"}
   ]
]

var result = dictionary_example.reduce(function(accumulator, element){
    
    return accumulator.concat(element);

},[]).reduce(function(accumulator, element){

    if(!accumulator[element.country])
        accumulator[element.country] = {[element.condition]: 1};
    else
        accumulator[element.country][element.condition] = (accumulator[element.country][element.condition] ||  0) + 1;

    return accumulator;
    
}, {});

console.log(result)

Answer 4

var dictionary_example = [
   [
      {country: "germany", condition: "cloudy"},
      {country: "italy", condition: "sunny"}
   ],
   [
      {country: "germany", condition: "windy"},
      {country: "italy", condition: "rainy"}
   ],
   [
      {country: "germany", condition: "snowy"},
      {country: "italy", condition: "foggy"}
   ]
]

var result = dictionary_example.reduce(function(accumulator, element){
    
    return accumulator.concat(element);

},[]).reduce(function(accumulator, element){

    if(!accumulator[element.country])
        accumulator[element.country] = {[element.condition]: 1};
    else
        accumulator[element.country][element.condition] = (accumulator[element.country][element.condition] ||  0) + 1;

    return accumulator;
    
}, {});

console.log(result)

Answer 5

Answer №3

When dealing with arrays of arrays, you have the option to flatten those arrays using a depth of 2. Following that, you can leverage the Array.prototype.reduce function to construct the desired output.

const arr = [   [      {country: "georgia", value: "sunny"},      {country: "france", value: "rainy"}   ],   [      {country: "georgia", value: "sunny"},      {country: "france", value: "gloomy"}   ],   [      {country: "georgia", value: "rainy"},      {country: "france", value: "dry"}   ]];
const result = arr.flat(2).reduce((a, {country, value}) => {
  const current = (a[country] ?? (a[country] = {[value]: 0}));
  a[country][value] = (a[country][value] ?? 0) + 1;
  return a;
}, {});

console.log(result);

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

Answer 6

When dealing with arrays of arrays, you have the option to flatten those arrays using a depth of 2. Following that, you can leverage the Array.prototype.reduce function to construct the desired output.

const arr = [   [      {country: "georgia", value: "sunny"},      {country: "france", value: "rainy"}   ],   [      {country: "georgia", value: "sunny"},      {country: "france", value: "gloomy"}   ],   [      {country: "georgia", value: "rainy"},      {country: "france", value: "dry"}   ]];
const result = arr.flat(2).reduce((a, {country, value}) => {
  const current = (a[country] ?? (a[country] = {[value]: 0}));
  a[country][value] = (a[country][value] ?? 0) + 1;
  return a;
}, {});

console.log(result);

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

Ways to determine the occurrence rate of a specific value within a collection of dictionaries?

Answer №1

Answer №2

Answer №3

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