[Chartjs]-How to Convert an Array of Objects into an Object of Associative Arrays in Javascript

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2👍

✅

You could take an object and get all keys with ther values in single array.

var data = { chart: [{ date: "2018-10-29", done: 3, todo: 10 }, { date: "2018-10-30", done: 4, todo: 7 }, { date: "2018-10-31", done: 5, todo: 12 }] },
    result = { chart: data.chart.reduce((r, o) => {
            Object.entries(o).forEach(([k, v]) => (r[k] = r[k] || []).push(v));
            return r;
        }, {})
    };
    
console.log(result);
.as-console-wrapper { max-height: 100% !important; top: 0; }

1👍

What about using reduce ?

const output = input.reduce((acc, curr) => ({
  date: acc.date.concat(curr.date),
  done: acc.done.concat(curr.done),
  todo: acc.todo.concat(curr.todo),
}), { date: [], done: [], todo: [] });

const chartData = {
  chart: [output],
};

Reference for reduce is here : https://developer.mozilla.org/fr/docs/Web/JavaScript/Reference/Objets_globaux/Array/reduce

0👍

Here’s a very explicit solution. There may be some slicker Javascript solutions; certainly you can do multiple .map calls, but that makes it less efficient.

// Variables
var dates = [];
var doneValues = [];
var todoValues = [];

// Loop through the original data once, collect the data.
originalJSON.forEach(function(data) {
  dates.push(data["date"]);
  doneValues .push(data["done"]);
  todoValues .push(data["todo"]);
});

// Put it all together.
return {"chart": [{"date": dates, "done": doneValues , "todo": todoValues}]};

Modify it to suit your needs.

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