flatten array
by Tom M
JavaScript
let arr = [5,[1, 2],[3, 4, 5], [6, 7, 8, 9]];
let result = [];
function arrayFlatten(array) {
array.forEach(function(x) {
if (Array.isArray(x)) {
arrayFlatten(x);
} else {
result.push(x);
}
})
return result
}
console.log(arrayFlatten(arr));