---
title: Nesting For Loops
---
## Nesting For Loops
Remember to use Read-Search-Ask if you get stuck. Try to pair program :busts_in_silhouette: and write your own code :pencil:
:checkered_flag: Problem Explanation:
If you have a multi-dimensional array, you can use the same logic as the prior waypoint to loop through both the array and any sub-arrays.
Here is an example:
```
var arr = [
[1,2], [3,4], [5,6]
];
for (var i=0; i < arr.length; i++) {
for (var j=0; j < arr[i].length; j++) {
console.log(arr[i][j]);
}
}
```
This outputs each sub-element in arr
one at a time. Note that for the inner loop, we are checking the length of arr[i], since arr[i] is itself an array.
multiplyAll
so that it multiplies the product
variable by each number in the sub-arrays of arr
.length
and not the overall array.
try to solve the problem now
:speech_balloon: Hint 2i
and j
when multiplying the product.
try to solve the problem now
:speech_balloon: Hint 3arr[i]
when you multiply the sub-arrays with the product
variable.
try to solve the problem now
Spoiler Alert!
arr
in the i
for loop and the arr[i]
length in the j
for loop.product
variable by itself because it equals 1, and then multiply it by the sub-arrays.arr[i]
and j
.