Convert array of javascript object to array array

Question

In ES6, I was looking for an elegant way to convert this array:

var src = [{x:1,y:'a'},{x:2,y:'b'}];

To this array:

var desc = [[1,2],["a","b"]];

Which contains an array of all properties and one array for all values.

For this, I wrote this code:

var src = [{x:1,y:'a'},{x:2,y:'b'}];

var prop1 = [];
var prop2 = [];

src.forEach(item => {
    prop1.push(item.x)
    prop2.push(item.y);
});

var desc = [prop1, prop2];

It works great, but it's quite long, so I'm looking for a possible improvement and short code.

Answer 1

You name the requisite order (because the order of the keys in the object is not guaranteed), and then display the array src, retrieving the correspondence correction value.

var src = [{x:1,y:'a'},{x:2,y:'b'}]

var props = ['x', 'y'];

var result = props.map(prop => src.map(x => x[prop]))

console.log(result)

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Answer 2

You can use .reduce():

let src = [{x: 1, y: 'a'}, {x:2, y: 'b'}];

let result = src.reduce((a, c) => (a[0].push(c.x), a[1].push(c.y), a), [[], []]);

console.log(result);

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

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Docs:

• Array.prototype.reduce()
• Array.prototype.push()
• Comma Operator

Answer 3

, .

var src = [{ x: 1, y: 'a' }, { x: 2, y: 'b' }],
    desc = [];

src.forEach(o => Object.keys(o).forEach((k, i) => (desc[i] = desc[i] || []).push(o[k])));

console.log(desc);

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