将数据从一种对象数组转换为另一种对象

Question

There is a set of data that comes dynamically from the server and looks like this:

dataSet = [
 {vid: "General uneven corrosion", mk: "Visual measurement control",  ver: "95"}, 
 {vid: "General uneven corrosion", mk: "Ultrasonic thickness measurement", ver: "95"},
 {vid: "General uneven corrosion", mk: "Ultrasonic flaw detection", ver: "80"},
 {vid: "General uneven corrosion", mk: "Radiographic control", ver: "80"},
 {vid: "General uneven corrosion", mk: "Eddy current control", ver: "60"},
 {vid: "General uneven corrosion", mk: "Magnetic control", ver: "20"},
 {vid: "General uneven corrosion", mk: "Metallographic research", ver: "20"},
 {vid: "Increase in strength characteristics", mk: "Mechanical property studies", ver: "80"},
 {vid: "Increase in strength characteristics", mk: "Coercimetry", ver: "40"},
 {vid: "Increase in strength characteristics", mk: "Metallographic research", ver: "40"},
 {vid: "Increase in hardness", mk: "Mechanical property studies", ver: "95"},
 {vid: "Increase in hardness", mk: "Coercimetry", ver: "60"},
 {vid: "Increase in hardness", mk: "Metallographic research", ver: "40"},
 {vid: "Decreased ductility", mk: "Coercimetry", ver: "60"},
 {vid: "Decreased ductility", mk: "Mechanical property studies", ver: "60"},
 {vid: "Decreased ductility", mk: "Acoustic emission control", ver: "60"},
 {vid: "Decreased ductility", mk: "Magnetic control", ver: "60"},
 {vid: "Decreased ductility", mk: "Eddy current control", ver: "40"},
 {vid: "Decreased ductility", mk: "Metallographic research", ver: "40"},
 {vid: "Decreased ductility", mk: "Visual measurement control", ver: "20"}
];

To plot a grouped bar chart graph using D3, I need to transform the data into the following array of objects:

data = [
  {State: "General uneven corrosion", Visual measurement control: 95, Ultrasonic thickness measurement: 95, Ultrasonic flaw detection: 80, Radiographic control: 80, Eddy current control: 60, Magnetic control: 20, Metallographic research: 20, Mechanical property studies: 0, Coercimetry: 0, Acoustic emission control: 0},
  {State: "Increase in strength characteristics", Visual measurement control: 0, Ultrasonic thickness measurement: 0, Ultrasonic flaw detection: 0, Radiographic control: 0, Eddy current control: 0, Magnetic control: 0, Metallographic research: 40, Mechanical property studies: 80, Coercimetry: 40, Acoustic emission control: 0},
  {State: "Increase in hardness", Visual measurement control: 0, Ultrasonic thickness measurement: 0, Ultrasonic flaw detection: 0, Radiographic control: 0, Eddy current control: 0, Magnetic control: 0, Metallographic research: 40, Mechanical property studies: 95, Coercimetry: 60, Acoustic emission control: 0},
  {State: "Decreased ductility", Visual measurement control: 20, Ultrasonic thickness measurement: 0, Ultrasonic flaw detection: 0, Radiographic control: 0, Eddy current control: 40, Magnetic control: 60, Metallographic research: 40, Mechanical property studies: 60, Coercimetry: 60, Acoustic emission control: 60}, 
  columns: ["State", "Visual measurement control", "Ultrasonic thickness measurement", "Ultrasonic flaw detection", "Radiographic control", "Eddy current control", "Magnetic control", "Metallographic research", "Mechanical property studies", "Coercimetry", "Acoustic emission control"]
  y: "Detectability"
];

This is where the every State takes on a unique value of vid and every object of final data array contains set of mk . For each object, the order of mk in set is the same, and the value of each mk corresponds to the initial dataSet, or takes 0 if there is no data for this species.

I can get arrays of unique values of a particular key,

let allMk = []
dataSet.forEach(item => {
     allMk.push(item.mk)
});
let allMkUni = new Set (allMk)

but I do not understand how to correctly convert objects to the desired form. Help please. Thanks

Answer 1

Probably easiest to reduce() to an intermediate object, and then map() the entries to an array:

 const data = [ {vid: "General uneven corrosion", mk: "Visual measurement control", ver: "95"}, {vid: "General uneven corrosion", mk: "Ultrasonic thickness measurement", ver: "95"}, {vid: "General uneven corrosion", mk: "Ultrasonic flaw detection", ver: "80"}, {vid: "General uneven corrosion", mk: "Radiographic control", ver: "80"}, {vid: "General uneven corrosion", mk: "Eddy current control", ver: "60"}, {vid: "General uneven corrosion", mk: "Magnetic control", ver: "20"}, {vid: "General uneven corrosion", mk: "Metallographic research", ver: "20"}, {vid: "Increase in strength characteristics", mk: "Mechanical property studies", ver: "80"}, {vid: "Increase in strength characteristics", mk: "Coercimetry", ver: "40"}, {vid: "Increase in strength characteristics", mk: "Metallographic research", ver: "40"}, {vid: "Increase in hardness", mk: "Mechanical property studies", ver: "95"}, {vid: "Increase in hardness", mk: "Coercimetry", ver: "60"}, {vid: "Increase in hardness", mk: "Metallographic research", ver: "40"}, {vid: "Decreased ductility", mk: "Coercimetry", ver: "60"}, {vid: "Decreased ductility", mk: "Mechanical property studies", ver: "60"}, {vid: "Decreased ductility", mk: "Acoustic emission control", ver: "60"}, {vid: "Decreased ductility", mk: "Magnetic control", ver: "60"}, {vid: "Decreased ductility", mk: "Eddy current control", ver: "40"}, {vid: "Decreased ductility", mk: "Metallographic research", ver: "40"}, {vid: "Decreased ductility", mk: "Visual measurement control", ver: "20"} ]; const result = Object.entries(data.reduce((a, {vid, mk, ver}) => { a[vid] = a[vid] || {}; a[vid][mk] = ver; return a; }, {})).map(([k, v]) => ({State: k, ...v})); console.log(result)