function fooA(numOfRows: number, numOfCols: number) {
	const rows = new Array(numOfRows);
	return [...rows].map((_) => {
		const cols = new Array(numOfCols);
		return cols;
	});
}
function fooB(numOfRows: number, numOfCols: number) {
	return [...Array(numOfRows)].map((_) => Array(numOfCols));
}
function fooC(numOfRows: number, numOfCols: number) {
	const rows = new Array(numOfRows);
	return [...rows].map((_) => Array(numOfCols));
}