What is the most efficient way to convert the data below in node.js? Any help would be much appreciated. Thanks!

I have some data that looks like this ->

const inputdata = {
  data1: [5.0, 10.0, 50.0, 100.0, 500.0],
  data2: [5.0, 10.0, 50.0, 100.0, 500.0],
  data3: [5.0, 10.0, 50.0, 100.0, 500.0],
};

and I need to convert it into this ->

[
  { data1: 5.0, data2: 5.0, data3: 5.0 },
  { data1: 10.0, data2: 10.0, data3: 10.0 },
  { data1: 50.0, data2: 50.0, data3: 50.0 },
  { data1: 100.0, data2: 100.0, data3: 100.0 },
  { data1: 500.0, data2: 500.0, data3: 500.0 },
]

Code attempt ->

const inputdata = {
  data1: [5.0, 10.0, 50.0, 100.0, 500.0],
  data2: [5.0, 10.0, 50.0, 100.0, 500.0],
  data3: [5.0, 10.0, 50.0, 100.0, 500.0],
};
const outputdata = [];

Object.keys(inputdata).forEach(key => {
  let value = inputdata[key];

  if (key === "data1"){
    for (let i = 0; i < value.length; i  ) {
      outputdata.push({ data1: 0, data2: 0, data3: 0 });
    }
  }
}
Object.keys(inputdata).forEach(key => {
  let value = inputdata[key];

  if (key === "data1") {
    for (let i = 0; i < value.length; i  ) {
      outputdata[i].data1 = value[i];
    }
  }
  if (key === "data2") {
    for (let i = 0; i < value.length; i  ) {
      outputdata[i].data2 = value[i];
    }
  }
  if (key === "data3") {
    for (let i = 0; i < value.length; i  ) {
      outputdata[i].data3 = value[i];
    }
  }
}
console.log(inputdata);
console.log(outputdata);

CodePudding user response：

You could transpose the data and build new objects from data.

const
    data = { data1: [5, 10, 50, 100, 500], data2: [5, 10, 50, 100, 500], data3: [5, 10, 50, 100, 500] },
    result = Object
        .entries(data)
        .reduce((r, [k, a]) => a.map((v, i) => ({ ...r[i], [k]: v })), []);

console.log(result);

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CodePudding user response：

Used techniques of the below provided step by step example code ...

• Object.assign

• Object.values

• Array.prototype.map

• Array.prototype.reduce

// reducer function which transposes
// a table into a matrix and vice versa.
function transpose(result, row) {
  return row.reduce((matrix, value, idx) => {

    (matrix[idx] ??= []).push(value);
    return matrix;

  }, result);
}

const inputdata = {
  data1: [5.0, 10.0, 50.0, 100.0, 500.0],
  data2: [5.0, 10.0, 50.0, 100.0, 500.0],
  data3: [5.0, 10.0, 50.0, 100.0, 500.0]
};
console.log(
  Object

    // convert `inputdata` into a table
    // ... an array of row like arrays.
    .values(inputdata)
);
console.log(
  Object

    // - convert `inputdata` into a table
    //   ... an array of row like arrays.
    .values(inputdata)

    // - then transpose the table into a matrix.
    .reduce(transpose, [])
);
console.log(
  Object

    // - convert `inputdata` into a table
    //   ... an array of row like arrays.
    .values(inputdata)

    // - then transpose the table into a matrix.
    .reduce(transpose, [])

    // - then convert/map matrix 
    //   into an array of objects.
    .map(vector =>
      vector.reduce((object, value, idx) =>

        Object.assign(object, {
          [`data${ idx   1 }`]: value,
        }), {}        
      )
    )
);

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