Transform nested arrays of integers into a flat array of integers - javascript

Question

The work context of my question is data visualization. It is correct transforming nested arrays of integers into a flat array of integers in this way?

var inputArray = [[1, 2, [3]],4,[5, [6, [7,8],[9]]],10];

var inputArrayStr = inputArray.toString(); 
var outputArrayInt = JSON.parse("[" + inputArrayStr + "]");

console.log(outputArrayInt); // --> [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ]

Answer 1

Actually:

Take Array#flat with Infinity as parameter for a flat array of all levels:

const
    input = [[1, 2, [3]], 4, [5, [6, [7, 8], [9]]], 10],
    output = input.flat(Infinity);

console.log(output);

---

Older Answer:

I suggest to use a special function for this task.

function flat(a) {
    var b = [];
    a.forEach(function (c) {
        if (Array.isArray(c)) {
            b = b.concat(flat(c));
        } else {
            b.push(c);
        }
    });
    return b;
}

var inputArray = [[1, 2, [3]], 4, [5, [6, [7, 8], [9]]], 10],
    outputArray = flat(inputArray);

document.write('<pre>' + JSON.stringify(outputArray, 0, 4) + '</pre>');