JavaScript achatando uma matriz
let arr = [
[1, 2],
[3, 4],
[5, 6][7, 8, 9],
[10, 11, 12, 13, 14, 15]
];
let flatArray = arr.reduce((acc, curVal) => {
return acc.concat(curVal)
}, []);
//Output: [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 ]
Elated Earthworm