Javascript reformat or map an array of objects to a new array of new objects? like reformating it

Question

I'm new to Arrays and objects so I was the whole day stuck at making this task I have a this JSON file or array lang (JavaScript) i was searching on StackOverflow also but can't understand them really well:

[
  { "date": "1959:01", this"1": 138.89, "2": 139.39, "3": 139.74, "4": 139.69, "5": 140.68, "6": 141.17 },
  { "date": "1959:07", "1": 141.7, "2": 141.9, "3": 141.01, "4": 140.47, "5": 140.38, "6": 139.95 },
  { "date": "1960:01", "1": 139.98, "2": 139.87, "3": 139.75, "4": 139.56, "5": 139.61, "6": 139.58 },
  { "date": "1960:07", "1": 140.18, "2": 141.31, "3": 141.18, "4": 140.92, "5": 140.86, "6": 140.69 },
  { "date": "1961:01", "1": 141.06, "2": 141.6, "3": 141.87, "4": 142.13, "5": 142.66, "6": 142.88 },
  { "date": "1961:07", "1": 142.92, "2": 143.49, "3": 143.78, "4": 144.14, "5": 144.76, "6": 145.2 },
  { "date": "1962:01", "1": 145.24, "2": 145.66, "3": 145.96, "4": 146.4, "5": 146.84, "6": 146.58 },
  { "date": "1962:07", "1": 146.46, "2": 146.57, "3": 146.3, "4": 146.71, "5": 147.29, "6": 147.82 },
  { "date": "1963:01", "1": 148.26, "2": 148.9, "3": 149.17, "4": 149.7, "5": 150.39, "6": 150.43 },
  { "date": "1963:07", "1": 151.34, "2": 151.78, "3": 151.98, "4": 152.55, "5": 153.65, "6": 153.29 },
  { "date": "1964:01", "1": 153.74, "2": 154.31, "3": 154.48, "4": 154.77, "5": 155.33, "6": 155.62 },
  { "date": "1964:07", "1": 156.8, "2": 157.82, "3": 158.75, "4": 159.24, "5": 159.96, "6": 160.3 },
  { "date": "1965:01", "1": 160.71, "2": 160.94, "3": 161.47, "4": 162.03, "5": 161.7, "6": 162.19 },
  { "date": "1965:07", "1": 163.05, "2": 163.68, "3": 164.85, "4": 165.97, "5": 166.71, "6": 167.85 },
  { "date": "1966:01", "1": 169.08, "2": 169.62, "3": 170.51, "4": 171.81, "5": 171.33, "6": 171.57 },
  { "date": "1966:07", "1": 170.31, "2": 170.81, "3": 171.97, "4": 171.16, "5": 171.38, "6": 172.03 }
]

Those are like an income for a company for a specified number of years like in the beginning 1959:01 from 1 to 6 are the first 6 months of the year and the same year 1956:07 but diff in ":07" are the values of the last 6 months (1 to 6) of same year so I wanna make the output as follows each month with it's value and year with the easiest code to understand please.

  [
  {
"year": 1996,
"month": 1,
"value": 88512.12
  },
  {
"year": 1996,
"month": 2,
"value": 71212.12
  },
  {
"year": 1996,
"month": 3,
"value": 1212.12
  },
  {
"year": 1996,
"month": 4,
"value": 754212.12
  },{
"year": 1996,
"month": 5,
"value": 545221.12
  }
  
]

Appreciate help quite a lot.

this is my code and don't think it helps it's out of the way i think i wish a new easier and more readable one (edited i think this one is more logic than the other one):

const month = {};
let i = 1
let m = 1
for (let obj of finance) {
  const year = obj["date"].split(":")[0];
  month[m] = obj[`${m}`]
  // month = {...month}
  value = month[0]
  console.log('this is the value >>>>>>>>>>' + value)
  formated[year] = {year ,month}
  // delete formated[year]["date"];
  i++
  if (m < 6 ) {m++}
}

console.log(formated,"<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>", month);

fs.writeFileSync(
  path.resolve(__dirname, "Try1.json"),
  JSON.stringify(formated)
);

Answer 1

If I understand your question correctly, then you could do something like this:

const financialResults = [
  { "date": "1959:01", "1": 138.89, "2": 139.39, "3": 139.74, "4": 139.69, "5": 140.68, "6": 141.17 },
  { "date": "1959:07", "1": 141.7, "2": 141.9, "3": 141.01, "4": 140.47, "5": 140.38, "6": 139.95 },
  { "date": "1960:01", "1": 139.98, "2": 139.87, "3": 139.75, "4": 139.56, "5": 139.61, "6": 139.58 },
  { "date": "1960:07", "1": 140.18, "2": 141.31, "3": 141.18, "4": 140.92, "5": 140.86, "6": 140.69 },
  { "date": "1961:01", "1": 141.06, "2": 141.6, "3": 141.87, "4": 142.13, "5": 142.66, "6": 142.88 },
  { "date": "1961:07", "1": 142.92, "2": 143.49, "3": 143.78, "4": 144.14, "5": 144.76, "6": 145.2 },
  { "date": "1962:01", "1": 145.24, "2": 145.66, "3": 145.96, "4": 146.4, "5": 146.84, "6": 146.58 },
  { "date": "1962:07", "1": 146.46, "2": 146.57, "3": 146.3, "4": 146.71, "5": 147.29, "6": 147.82 },
  { "date": "1963:01", "1": 148.26, "2": 148.9, "3": 149.17, "4": 149.7, "5": 150.39, "6": 150.43 },
  { "date": "1963:07", "1": 151.34, "2": 151.78, "3": 151.98, "4": 152.55, "5": 153.65, "6": 153.29 },
  { "date": "1964:01", "1": 153.74, "2": 154.31, "3": 154.48, "4": 154.77, "5": 155.33, "6": 155.62 },
  { "date": "1964:07", "1": 156.8, "2": 157.82, "3": 158.75, "4": 159.24, "5": 159.96, "6": 160.3 },
  { "date": "1965:01", "1": 160.71, "2": 160.94, "3": 161.47, "4": 162.03, "5": 161.7, "6": 162.19 },
  { "date": "1965:07", "1": 163.05, "2": 163.68, "3": 164.85, "4": 165.97, "5": 166.71, "6": 167.85 },
  { "date": "1966:01", "1": 169.08, "2": 169.62, "3": 170.51, "4": 171.81, "5": 171.33, "6": 171.57 },
  { "date": "1966:07", "1": 170.31, "2": 170.81, "3": 171.97, "4": 171.16, "5": 171.38, "6": 172.03 }
]

// Extract semester and year: assign 2 if entry corresponds to second semester or 1 if it corresponds to the first
// semester in the year
const extractYearAndSemester = date => ({ year: date.split(":")[0], semester: date.split(":")[1] > 6 ? 2 : 1 })

// For each entry, return an array of objects with the desired properties
// Finally, flatten the array, so you don't end up with an array of arrays
const formatResults = arr => arr.
  flatMap(entry => {
  const { year, semester } = extractYearAndSemester(entry.date)
  let semesterResults = []

  for (let key in entry) {
    if (parseInt(key)) {
      semesterResults.push({
        year,
        month: semester === 1 ? parseInt(key) : parseInt(key) + 6,
        value: entry[key]
      })
    }
  }

  return semesterResults
  })

console.log(formatResults(financialResults))

Answer 2

try loop through data and parse property of each record as below. In the end of the outer loop you will have data with your desired format in monthData variable;

var data = [
      { "date": "1959:01", "1": 138.89, "2": 139.39, "3": 139.74, "4": 139.69, "5": 140.68, "6": 141.17 },
      { "date": "1959:07", "1": 141.7, "2": 141.9, "3": 141.01, "4": 140.47, "5": 140.38, "6": 139.95 },
    ];
     var monthData = [];
    
      for (let index = 0; index < data.length; index++) {
        var item =data[index];
        var dateArray = item.date.split(":");
        var year = dateArray[0];
        var baseMonth = Number(dateArray[1]);
        for (var key in item) {
          if (item.hasOwnProperty(key)) {
              var val = item[key];
              if (String(val).indexOf(":")== -1) {
    
              monthData.push({
                year:year ,
                month:  baseMonth-1 + Number(key),
                value: val,
              });
            }
          }
        }
        
      }

Answer 3

Read up about this package it will make your life easier: use of _map - Lodash