Iterating through the ordinary for in JavaScript

Arrays can also be iterated not through the for-of loop, but using the ordinary for:

let arr = [[1, 2, 3, 4, 5], [6, 7, 8], [9, 10]];

for (let i = 0; i < arr.length; i++) {
	for (let j = 0; j < arr[i].length; j++) {
		console.log(arr[i][j]);
	}
}

Solve the previous two tasks through the loop for.